The Vanishing Ray (also known as The Invisible Ray) is a comic strip starring Lady Penelope that appeared in TV Century 21 comic issues 44-51 and was also the departure strip in particular for that comic before Lady Penelope was given a comic of her own.
It also appeared in the fourth book of the 1992 Thunderbirds Comic album called "Lift Off" and the Thunderbirds Comic Collection Volume 1.
Penelope receives a strange invisible ray projecting torch in the post, with no clue of who sent it to her. But this is just the beginning of the trouble when two powerful adversaries are also interested in the device...
At Creighton-Ward mansion, Parker gives Lady Penelope her morning post. She discovers the small package and unwraps it first finding a small torch. Her ladyship turns it on and to their surprise it gives a pink beam that makes half of the table disappear and then the tea tray. Penelope explains to a confused Parker about how the ray works and find no return address on the package giving them no clue on who sent it to them.
Meanwhile at the headquarters of the British Secret Service at Whitehall, they receive an anonymous letter stating Lady Penelope in possession of an invisible ray. Fearing that the device would be dangerous in the wrong hands, the head of the service sends one of his top agents Steele to investigate.
At the same moment, the same letter is received by The Hood at his temple in Malaysia. He decides he must have it as it would be the perfect cover to find out the world's top secrets. He heads for England at once, vowing to get the ray even if he has to kill Penelope first. He uses a false passport to enter the country, hires a car and heads for Creighton-Ward mansion.
Steele arrives there first and pretends to be a cookbook salesman so he can enter the mansion. Penelope kindly invites him to stay for tea and while she rings for Parker, Steele spots the ray torch on the half-vanished table and quickly pockets it before Parker comes with tea. After thanking her ladyship, Parker shows him to the door and temptingly picks his pockets. To his surprise he finds the torch and returns it to the equally astonished Lady Penelope.
Later the Hood arrives and uses the same ruse as Steele. Penelope again makes an invitation to tea. After seeing the ray on the table, the Hood upsets his tea as a distraction while he grabs the torch. He then leaves, making sure not to have his pockets picked. Lady Penelope then realises the torch is missing again while the Hood goes to his car, confident that he now has the power to be invisible himself.
When Parker realises that the Hood has taken it, Penelope holds up the real torch saying that she switched them with an ordinary one as a safety precaution. Meanwhile the Hood tests the torch on a seat in the car. When nothing happens he angrily flings the torch aside realising he has been tricked and decides to get more help, unaware that the torch has a small transmitting signal cell monitored by Penelope and Parker.
He stops at a place owned by a burglar named Big George and hires him and his men to break into the house for him tonight.
Lady Penelope decides to keep the ray in a secret underground safe and to turn on the security alarms to keep them away.
Back at the British Secret Service headquarters, the head is angry with Steele for failing to bring the ray and decides to bring Lady Penelope in for questioning. Many agents led by Steele arrive at the mansion and arrest her ladyship and Parker. Before they leave Penelope quickly sets the alarms.
The Hood and the hired men arrive and are unable to break in due to Lady Penelope's alarm systems. The Police arrive to arrest the burglars, but the Hood gets away vowing revenge.
The agents of the British Secret Service question Lady Penelope who tells of how Steele took the device on his visit, as a result her ladyship is set free and Steele is then questioned by his fellow agents on the whereabouts of the ray even though he keeps telling them that Parker stole it back.
As they leave the building, Penelope decides to call FAB 1 to pick them up unaware that the Hood is lurking in an alley nearby with a gun aimed at her ladyship. Penelope bends down to remove her shoe that has a built in radio to contact the rolls-royce, narrowly missing the Hood's shot that goes through the glass window of the building.
Her ladyship and Parker flee before they are detained for questioning again and just as the Hood is about to pursue them, an armed agent appears and chases the crook. The Hood eludes him but angrily vows that he will find Penelope yet.
Meanwhile Penelope finally uses her shoe communicator to call the rolls-royce and they head for home, but the Hood is still pursuing them and from his car fires point blank range at FAB 1 so he can steal Penelope's keys to break into the mansion. Parker then uses the oil slip on the road causing the Hood's car to crash. The furious crook gets out of the wrecked car and vows that Penelope will die.
Back at the mansion, Penelope relaxes and Parker suggests that they should analyse it to see who sent it to them. Suddenly there is a knock on the door and after a warning from Penelope knowing they have not seen the last of the Hood, he opens it to see a policeman on the doorstep.
He explains about the break in earlier and asks to see her ladyship for a statement. Parker lets him in and is knocked unconscious by the man.
The policeman enters the living room and reveals himself to Penelope as the Hood in disguise. He ties her up and threatens to shoot her dead if she doesn't tell him where the ray is, but Penelope won't co-operate so he gives her a few warning shots. When Penelope still won't talk, he gets ready for the final kill, but Penelope activates a switch on the arm of her chair which releases a large chandelier that falls on top of the crook and knocks him unconscious.
Parker then recovers and enters the room, unties Penelope and leaves the Hood on the doorstep of the Secret Service Headquarters. Inside the agents deduce that Steele was telling the truth all along and they should interrogate Penelope once again. One of the agents go out to collect the milk and find the Hood on the doorstep. They bring him inside for questioning, but the crook refuses to talk. The only charge against him is illegal entry into the country, so they arrange for the authorities to send him back to Malaysia.
Next morning Lady Penelope and Parker analyse the invisible ray torch and find out that their components were made by someone of vast intelligence who sent it to her. Penelope is still confused as why the item was sent to her.
Parker arrives with the morning post that contains a strange postcard saying "Will explain all at 10. Thunderbirds are nearly go." At 10 o'clock, there is a knock on the door and the person turns out to be her friend Jeff Tracy who explains that his technician Brains had invented the ray and everything that had happened to her was a test to see how well she could handle the british end of International Rescue by holding onto something important despite difficulties. She passed the test in flying colours becoming their new London agent. Brains then appears with a new table to replace the one that half disappeared.
Jeff then tells Penelope a plan of how the British Secret Service will leave her alone. She enters the main headquarters and goes to the head of the service who shows her a file which has enough evidence to send her to prison. She uses the ray on it which makes it invisible and gives the ray to the astonished head.
They all reach the airport with Jeff and Brains saying their goodbyes and pleased to have her ladyship in their organisation. Parker is a little sad of all the excitement being over but Penelope tells him that they are now part of International Rescue.