More electronic puppet action in this, the second of the 'Thunderbirds' films. This time round, Tracy Island's resident genius Brains designs a revolutionary new aircraft, the Skyship One, only to see it hijacked on its maiden voyage. The Thunderbirds team get ready to come to the rescue, but with Alan Tracy and Lady Penelope trapped on board the Skyship, and Thunderbirds 1 and 2 heading into a trap set up by the hijackers, it's not going to be that easy.