Bob Williams has fallen over a cliff, and is now trapped on a ledge. He says his leg hurts and he knows he has to get help. He manages to grab his bag and pulls out a walkie talkie from it. He puts in a call to International Rescue, which John picks up in Thunderbird 5. Bob says that he's fallen off a cliff and thinks his leg is broken. He asks if International Rescue can hear him and asks to be saved. John says they're here, and asks if he's receiving him.

Bob says he's scared and asks them to send help. He hopes they've picked up his message. John contacts Tracy Island and explains about the call he received, but says he couldn't ask any questions because the boy was only transmitting. But he did stay on the air long enough for him to get a fix on him within a mile. Jeff tells Scott to go.

He tells Scott that John will give him directions once he's sky borne. John says he's worried about that kid, as he could panic and fall. Jeff tells him to watch out for him transmitting again, as he could then get a more precise fix on him. Scott takes off in Thunderbird 1 and heads to Australia. Meanwhile, Bob says it'll be dark soon, he should have been found by now. He starts calling out for help.

Scott reports he'll be in sight of the rescue zone three minutes from now. Jeff says the boy is down there somewhere, he'll have to try and locate him on the scanner. Scott flies Thunderbird 1 through the area and uses his craft's scanners to start searching. He soon finds Bob, who gets up and starts waving at him. Scott says he's spotted Bob, and he looks fit enough -he's on his feet and waving at him!

Jeff asks if he needs any help, but Scott says he can handle this one. He takes Thunderbird 1 down to land near to the cliff. A rope is soon lowered to where Bob is, so he grabs onto it. He gets pulled up and says International Rescue have arrived just in time, and have saved his life.

His brother, Tony, says it's alright -they do this all the time! Bob asks surely they'll take a reward, a couple of million or so. Tony says they don't take money, they just save people. They only ask for one thing: don't try to follow him when he leaves. Their base is secret, and please -no photographs. Scott has been watching nearby and says now, he's seen everything. He walks over to them and realizes that Bob never did need rescuing. He asks for an explanation.

Bob and Tony take Scott back to their home, where he meets their father. He says it's all his fault, but Bob tells him he can't blame himself. Scott says it's not a case of who's too blame, they just need to realize that while they were dealing with this call, someone really needing help could have lost their life. Williams says they realize the seriousness of the situation, and he's not trying to make excuses, but he asks Scott to look at it from the boy's point of view. Since their mother died, he's had to try and be a mother and a father to them. Life is pretty dreary around here for a couple of lively boys, so he tries to make it up to them. He made them these walkie talkies but as he keeps pretty busy at the weather station, they have to amuse themselves.

Bob and Tony say they play International Rescue all the time, it's their favorite game! Scott says he understands the situation, but this little escapade could have had very tragic results. Bob says they really are sorry, and Tony asks what he's going to do to them. Scott says there are several things he should do, but he's decided he's going to take them on a little trip. If it's ok with their dad, he's going to take them to International Rescue's headquarters, so they can see just how much trouble a false alarm can cause.

Bob and Tony board Thunderbird 1, which takes off and heads back to Tracy Island. Bob and Tony think this is great, so Scott tells them to hold tight -they're on their way.

At Tracy Island, Jeff tells Gordon, Alan and Virgil that with Scott bringing two such admirers as Tony and Bob here, they've really got to be on their toes. Brains then comes in and says Thunderbird 1's eta is two minutes. In Thunderbird 1, Scott tells Bob and Tony that International Rescue is a top secret project and must stay that way. Too many of the wrong guys would like to get their hands on the organization's secrets. Bob and Tony put on their blindfolds and tell Scott they can take Thunderbird 1 down now.

Thunderbird 1 lands back in the hidden swimming pool launch pad. In the Tracy Island kitchen, Tin-Tin tells Grandma that there is enough food here to feed an army! Grandma says an army maybe, but two growing youngsters, she's not so sure. Tin-Tin thinks Grandma really can cook, but Grandma just hopes she isn't out of practice. The trouble with living on a secret base is that visitors are few and far between. She asks where the boys are now, and Tin-Tin says "Uncle" Alan is taking them on the grand tour in the monocar.

Alan and the boys are in Thunderbird 2's launch bay, where all the pod vehicles are stored. Alan says these are some of the vehicles they use when they're out on rescue operations. These are just minor craft, but in just a moment they'll see something much more impressive. The monocar arrives in Thunderbird 3's bay. Bob says that's some spaceship, and Tony bets Scott is the only one allowed to pilot that one. Alan says he's the one who takes the control of the spaceship, although he does take Scott with him on call, just to keep him on course.

Lunch is then served, so everybody eats. Bob and Tony get through everything, and Grandma tells Tin-Tin they only just had enough. Bob says that was the best meal he's ever had. Brains asks them what they think of the base, did they enjoy their tour?

Bob says it was super, he wished he lived here. Tony says they understand now why they must not call them out without a good reason. Jeff says if they learnt that, then the trip was worthwhile. They've been really privileged getting to come to a top secret base like this. That's why they had to wear those blindfolds, so they wouldn't know which part of the world they're in. He then says they'd better be getting home, so he hands that over to Virgil. As Bob and Tony say their goodbyes, Virgil heads off to Thunderbird 2.

Bob and Tony are sent down to Thunderbird 2 via the passenger chute. They all board Thunderbird 2, so Bob and Tony put their blindfolds back on. Virgil moves Thunderbird 2 down the runway.

Scott thanks his father for letting him bring Bob and Tony do this. Jeff says the day they don't have time for things like that, it'll be a sad day. And besides, a thing like that isn't going to cause any harm. Thunderbird 2 blasts off and heads to Australia. Soon, news about Bob and Tony's adventure with International Rescue hits the press.

Tony says they've certainly made the news. Bob says that's quite a good photograph of the house. They decide to show their father, as he hasn't seen the papers yet. Williams takes a look at the paper, but he says it's a pity the press got hold of this story. He thinks someone might start to suspect things. The Hood reads the story and laughs, thinking about the claim that the place the boys live at is a weather station. He thinks this could be just what he has been looking for, and who would have thought that International Rescue would be the ones to lead him to it!

At the Australian Satellite HQ, Lieutenant Lansfield contacts Dunsley Tracker. Williams responds and says he's now on standby. Lansfield tells him that satellite alpha two zero is now coming up, and the radio photographs will be coming up to him. Williams says all systems are functioning and ends the call. He opens up a hidden computer, which starts printing photographs the satellite has taken.

Meanwhile, Bob tells Tony it's his turn to rescue him. Tony says he's going to go up to the old mine at Dunsley Hill. Bob says that's a job for Thunderbird 2. Bob says to give him a half hour start, he'll be ready by then. Bob goes to see his father, but realizes he's in the darkroom. Williams activates a view screen and says he's very busy in the darkroom, and won't be out for a couple of hours. Bob says they're going out to play, so Williams tells him not to forget what Mr. Tracy told him -keep their radios turned off.

Outside, the Hood is waiting near the home. He decides that before he makes a move, he wants to be sure where everyone is. He sees Tony leave the house and watches him go. He looks at a map and thinks Tony must be heading to the old mine, and that would keep the two boys out of the way. He pulls out a mask and disguises himself.

Tony arrives at the mine and thinks there should be a place for him to go somewhere. The Hood then arrives at the mine in his truck and sees Tony. Tony asks him what he's doing here. The Hood claims he's been sent out to survey this derelict mine. He then calls Tony by name -he says he saw his picture in the papers. He knows he has a brother called Bob too.

Tony says that's right, and Bob will be coming to look for him right now. He's looking for a good place to be rescued from, so the Hood says he knows just the place. Meanwhile, Bob is traveling towards the mien and tells Tony not to worry -International Rescue are on their way! He arrives at the mine in his Thunderbird 2.

But when he gets there, he sees some debris fall down at the mine entrance. He calls out Tony's name and says he doesn't think they should play around here. The Hood then appears, and says he's a surveyor who's looking this place over for the government. He did tell Tony they could play here, but now he thinks it's too dangerous. He tells Bob he should collect Tony and go home.

Bob says ok. The Hood asks him if his father is at home, and Bob says he is. He asks why, and the Hood says he might have to go and see him. He asks if his father is alone, and Bob says his father won't have any visitors in the house, he may not even see him. The Hood says he'll try not to bother him if he's working. Bob says his father is working in the darkroom. The Hood asks what that is, but Bob says he doesn't know, as he or Tony aren't allowed in there. He says there is a lot of equipment in there that breaks easily. The Hood asks where the darkroom is in the house, but Bob says he'll just go and get Tony.

Bob enters the mine, and asks Tony where he is, as the game is off. Tony is near a shaft and calls out, so Bob walks up to where he is. Outside, the Hood fires a powerful explosive into the mine. It detonates and causes widespread damage to the mine's main entrance.

Tony and Bob get knocked back, and fall down the shaft. The Hood returns to his truck and drives away from the mine. Tony and Bob are left buried under a lot of rubble.

At Tracy Island, Gordon says this is the life. Tin-Tin thinks he shouldn't get too comfortable, and Virgil says she's right -usually when they get a chance to put their feet up, they get an emergency call. Gordon thinks if they do get one, they should give it to Tony and Bob. At the Satellite HQ, Lansfield tells Williams that these photographs could show the installations they've been searching for. He should think they can arrange for a collection tomorrow. Williams says that's the news he's been wanting to hear, as once this project is successful, he'll be posted back to his old job. He'll be able to see more of the kids then instead of only during their school holidays.

The Hood then enters the home. He starts to take a look around, but Williams turns on a view screen and asks him who he is and what he's doing in here. The Hood takes his mask off and makes his eyes start glowing. He repeatedly tells Williams to open the door, but Williams says he must turn off the screen.

He manages to do so, but collapses afterwards. Back in the mine, Bob says they promised they wouldn't use the radio, but Tony says this is different -it really is an emergency! He calls International Rescue, and his call is picked up by John. Tony says they must come, as there was this guy who tricked them into the mine, when he and Bob were both in here he must have thrown a bomb. John recognizes his voice and asks if it's Tony and Bob. He says they were told not to involve them in their games.

Tony says this time it's true, and tells Bob to tell him. Bob says they really are trapped down a mine, and asks John to please listen. Above them part of the ceiling starts to crack open. John reports back to Tracy Island about what Bob and Tony called about, and says they had him believing their story.

Virgil thinks their story is bogus, and also thinks it's funny John started to believe them. Jeff says it's not John's fault. When kids play games, they really do believe them. Scott thought they were a couple of good kids, they tried to give them something special but they've let them down and broken their promises. Jeff says to forget it, as boys will be boys.

Tony asks why International Rescue didn't believe them. Bob says that nobody is going to find them here, they'll never get out -never! At the Satellite HQ, Lansfield tells Colonel Jameson that the photographs will be collected first thing tomorrow. Jameson says that feels like a long time to wait, and asks if they're safe there. Lansfield says it'll be like they're in Fort Knox. The Dunsley Tracker was placed so far in the Australian bush that he thinks tomorrow will be the earliest they can get there. He then sees a call coming in from Dunsley Tracker.

Williams says it's an emergency, and explains he still has the photographs, but someone is trying to get in here. Jameson tells him to state exactly what's going on, whilst also telling Lansfield to find out exactly how fast they can get some men there. Williams says he heard someone outside, and found it was some man he's never seen before. He guesses the intruder tried to hypnotize him, but he was able to turn the screen off. He can't face him, even with a gun. He then hears some noises outside.

The Hood has taken a blowtorch, and starts using it to burn through a wall. John reports to Tracy Island that he thinks Tony and Bob must have gone home, as they've stopped calling. Jeff says he knew they would if they took no notice. Meanwhile, Jameson finds out that it'd take three hours for some men to get to Dunsley Tracker. Lansfield says that station is in the middle of nowhere, even if they tried sending help from the nearest town it'd take them two hours to get there.

Jameson tells Williams they can't get any help to him for several hours. Williams says the guy is practically through. Jameson tells him to hold out as long as he can, but if the guy gets in, he must destroy those photographs in any way he can. He must not let the guy take possession of them. But he must not destroy them until he's absolutely certain the guy is through, as those photos are vital. Williams suggests contacting International Rescue, as they made it here in 35 minutes. They might not make it in time, but it's better than anything else.

In the mine, more debris falls down over Bob and Tony. Bob thinks it's going to collapse on top of them. Jameson calls International Rescue and says it's an emergency. John takes the call and relays it back to Tracy Island. Jeff says it all fits together, and those boys weren't playing -they must really be in the mine. Scott says someone must have wanted to get Bob and Tony out of the way. Virgil says whoever it is must now be trying to steal the secret photos. Jeff says they aren't a political organization, but those boys are in real danger, so they can't ignore a call like this. He tells Scott to go after Williams, and instructs Virgil and Alan to go to the mine and bring those two boys out.

Thunderbird 1 takes off, followed by Thunderbird 2. Gordon talks to Bob and Tony via radio and tells them to remember what he told them: the Thunderbirds are coming! Tony says they'll be brave.

Lansfield says International Rescue should be there very soon. He wonders if that character at the Williams' house could have known about the photos. Jameson says he doesn't know what to make of it, clearly they're dealing with no ordinary thief. Lansfield says there's that business with the two boys trapped in the mine, it's too cleverly contrived. Jameson says the guy went there to get his hands on those photographs, and it looks like he'll stop at nothing. Meanwhile, the Hood has almost cut through the wall.

Williams gets a lighter and is about to burn the photos, but then the Hood kicks down the door and calls out his name. As Williams turns around, the Hood's eyes start glowing. Williams ends up collapsing and drops the photos without having had the chance to destroy them.

Scott arrives near the home and lands Thunderbird 1. He gets on a hover bike and heads towards the home, just in time to see the Hood leave it. The Hood hears Scott calling out to him, but he ignores him and heads back to his truck.

He quickly starts the truck up and leaves, but is followed by Scott. Meanwhile, Virgil and Alan arrive at the mine. Virgil says he'll take Thunderbird 2 down now, and tells Alan to radio the base and tell them to keep the boys talking. That way, they can home in on their walkie talkie. Gordon tells Bob and Tony to keep talking, as Virgil and Alan have arrived, and they'll have them out of there in no time. Bob asks for them to hurry, as there's not much time.

Virgil and Alan arrive at a shaft. Alan thinks this way in is as good as any, so Virgil tells him to contact the boys whilst he gets the equipment ready. Alan tells Bob and Tony they're coming down now. Virgil shoots a bolt into a beam and attaches a cable to it. He and Alan put some harnesses on and then descend into the mine.

Tony says the roof is giving way, and thinks Alan and Virgil shouldn't come after them. Alan asks if Virgil can get a reading, and Virgil says he can. He leads Alan further into the mine, which continues to collapse. They have to wait a few seconds when some debris falls in front of them.

They then find Tony and Bob. Alan tells Virgil that when he lifts this beam, he needs to pull the boys clear. Alan lifts the beam up, allowing Virgil to pull Tony out first, followed by Bob. They clear out just in time, as the roof caves in and wrecks the place Tony and Bob had been trapped in.

Meanwhile, Scott is still chasing after the Hood. The Hood can see Scott in one of his mirrors, so he continues to drive fast. He drives up a canyon and loses control of his truck, which starts to slide. He ends up crashing over the edge of a cliff, causing him and his truck to fall.

His truck hits the ground below and explodes. Scott comes to a stop at the edge of the cliff and thinks that guy couldn't have stood a chance. He guesses that's the last crooked game that guy will ever try to play. He decides to head down there and collect those photographs. Meanwhile, the Hood has survived by snagging on a tree branch. He curses those foolish boys, their stupid father and International Rescue.

The branch then snaps, causing him to fall into the water below. Everyone else heads back to the Williams' home. Williams says he doesn't know what to say, as whilst they saved the photographs, they saved his son's lives. Scott says they're glad they were able to, he should have known that Tony and Bob wouldn't have broken their promise.

Tony says before tea there's something he and Bob want to show him. Scott heads up to their bedroom, where a launch chute for their Thunderbird 2 has been constructed. Bob says their dad fixed it up for them. Tony instructs Scott to lie on the table. Scott says he'll try anything once.

Tony tells Scott it's an emergency, so away he goes. Bob pulls on a rope which raises up the board Scott is on, causing him to slide down to Thunderbird 2. He lands on it and it sets off, but he can't get to the controls. He ends up driving right through barn.

Bob says they're sorry, and Tony thinks Scott is too heavy for their emergency exit. Scott says the things he does for International Rescue...