The TARDIS locks on to a distress signal and arrives in an extremely hot ship. When the Doctor opens a door and crew rush to close the door. The engines have stopped working, and there are 42 minutes before the ship crashes into a sun.
When the Doctor tries to get back to the TARDIS he is knocked back by the heat.
The Doctor thinks it is simple: repair the engine and steer away from the sun, until he sees the sabotaged engine. The Captain notices some crew are missing. The only other engines are the auxiliary engines, but they can only be controlled from the front of the ship, and there are 29 password sealed doors between them and the front of the ship.
Getting through the doors needs two people, and Martha offers to help out. As they set off the Captain gets a call from the infirmary where Korwin, the Captain's husband, is struggling. He is being controlled and has sabotaged the ship. To stabilise him Korwin is put in a stasis chamber.
With 32 minutes left Martha and Rile start work on first door. To open the door a random question, set by Riley and another crew member nine tours ago whilst drunk, is asked. There is one chance to guess the correct password to open the doors.
The Doctor checks with Abi on Korwin's status, but she is struggling to make sense of the data. In the stasis chamber Korwin is moving. In the engine room the Doctor is busy with the engine. He comes up with a plan to use the generator to jump start the ship.
Martha is stuck on one of the questions and uses her phone to call her mum to look up the answer on the Internet.
In the infirmary Korwin begins to move. When Abi calls for emergency assistance the Doctor rushes to help, but is too late to help as Korwin opens his eyes, and the heat emitted instantly burns Abi. All the Doctor finds is a scorch mark on the wall. Looking at Korwin's test results he sees the internal temperature of 100 degrees. Something has consumed him, and he is wandering the ship.
Korwin continues through the ship, and kills Lessak and Ashton, and goes after Martha and Riley. To escape they get into an escape pod. Martha calls for the Doctor as Ashton activates the escape pod. Korwin finds the Captain and says everything is her fault. He is about to attack when Scannell freezes him.
The Doctor confronts Ashton, and is in time to see the ship jettison the pod, and watches as the pod heads towards the sun. Ashton later finds the Captain in the infirmary where she uses the stasis chamber to freeze him.
The Doctor calls to Scannell for a space suit to make a rescue atempt. Ashton overloaded the escape pod controls, but there are backup controls outside the ship. The Doctor manages to lean out of the airlock and activate the magnetic controls, dragging the capsule back. As it returns the Doctor looks at the sun, and realises it is alive before being consumed. The Doctor, before being completely consumed, tells the Captain she has been using energy from the sun without realising it is a living organism, and it is the sun that is preventing them from leaving.
Martha uses the statis chamber on the Doctor. Ashton notices the power drain in medical centre and cuts the power at a critical time. The Captain goes down to sort out Ashton. With the power cut the Doctor tells Martha to vent the engines and give back everything that was taken by the ship.
The Captain lures Korwin into an airlock and opens the exterior, sucking her and Korwin outside. Riley and Scannell manage to make it to the front of the ship with one minute to spare. Martha commands them to vent the engines when the auxiliary engines fail to start. When the dump the fuel the sun leaves the Doctor, returning him to normal,and the engines fire up, allowing the ship to escape from the sun.
- Martha Jones: Freema Agyeman
- Kath McDonnell: Michelle Collins
- Francine Jones: Adjoa Andoh
- Riley Vashtee: William Ash
- Orin Scannell: Anthony Flanagan
- Hal Korwin: Matthew Chamber
- Dev Ashton: Gary Powell
- Abi Lerner: Vinette Robinson
- Erina Lessak: Rebecca Oldfield
- Sinister Woman: Elise Du Toit
- Double for Hal Korwin: Adrian Walker
- Henchmen: David Cordingley, Bernie Hodges
- Countdown Voice: Joshua Hill
|BBC 1||7. 42||Saturday, May 19, 2007 7:15 PM - 8:00 PM||7.4M||85|
Repeat Broadcasts on the BBC
|BBC 3||42||Sunday, May 20, 2007 8:00 PM - 8:45 PM||0.9M||89|
|BBC 3||42||Friday, May 25, 2007 9:00 PM - 9:45 PM||0.3M|
|BBC 3||42||Friday, July 20, 2007 7:00 PM - 7:45 PM|
|BBC 3||42||Tuesday, September 11, 2007 7:00 PM - 7:45 PM|
|BBC 3||42||Friday, December 14, 2007 8:00 PM - 8:45 PM|
|BBC 3||42||Thursday, January 10, 2008 7:00 PM - 7:45 PM|
|BBC 3||42||Monday, November 24, 2008 7:45 PM - 8:30 PM|
|BBC 3||42||Thursday, March 5, 2009 7:00 PM - 7:45 PM|
|BBC 3||42||Wednesday, May 20, 2009 7:00 PM - 7:45 PM|
|BBC 3||42||Tuesday, September 22, 2009 7:00 PM - 7:45 PM|
|BBC 3||42||Friday, November 13, 2009 7:00 PM - 7:45 PM|
|BBC 3||42||Tuesday, February 16, 2010 7:00 PM - 7:45 PM|
|BBC 3||42||Friday, October 29, 2010 7:45 PM - 8:30 PM|
|BBC 3||42||Saturday, March 3, 2012 7:00 PM - 7:45 PM|
- Upper Boat Studios, Trefforest
- Cwrt-y-Vil Road, Penarth
- Old NEG Glass Site, Trident Park, Glass Avenue, Cardiff Bay
- St. Regis Paper Company, Sudbrook Mill, Caldicot, Monmouthshire
The character Hal Korwin is a mistake in the credits. The character should be Korwin McDonnell