"Up from the Depths Part 1" is the sixth episode of the second season of Thunderbirds Are Go!, and was broadcast on 19th November 2016.
Deep in the Mariana Trench a survey team encounter the TV-21, a prototype Thunderbird vehicle that was flown by Jeff Tracy, when a systems failure causes the ship to be stranded on the seabed. International Rescue arrives to rescue the crew but the Mechanic suddenly takes control of the surveyor and uses it to crush Thunderbird 4. Gordon gets out just as his ship is destroyed and now must use the TV-21 to rescue the crew. Meanwhile, Lady Penelope and Parker are investigating into how the Hood is communicating with the Mechanic.
- Scott Tracy & Alan Tracy: Rasmus Hardiker
- Virgil Tracy & Gordon Tracy: David Menkin
- John Tracy: Thomas Brodie-Sangster
- Kayo: Angel Coulby
- Brains: Kayvan Novak
- Grandma Tracy: Sandra Dickinson
- Lady Penelope Creighton-Ward: Rosamund Pike
- Parker: David Graham
- The Mechanic: Chris Jarman
- Controller: Kayvan Novak (not seen on screen; voice only)
- Pilot Clarke: Chris Jarman
- Pilot Sontag: Alex Kelly
International Rescue Equipment Used
Non-International Rescue Equipment Used
- Main article: Up from the Depths Part 1/Transcript
- Both parts of Up from the Depths were screened to the public at a BAFTA event on October 1, 2016.
- TV-21's name originates from the TV Century 21 magazines which used to publish comic-book stories of Thunderbirds in the 1960's.
- Gordon finds his father's hat and remarks that he cannot believe they used to wear such hats. The hat is part of the original series' IR uniform, specifically worn by Virgil Tracy.
- Thunderbird 4 was attacked and destroyed in this episode, marking the first time a Thunderbird has been in destroyed in Thunderbirds Are Go!, and only the second time in the whole TV/film franchise (the first being Thunderbird 5 in the 2004 movie).
- This is the second time the Mechanic has directly targeted and attacked Thunderbird 4, and the third time overall that he has specifically targeted a Thunderbird.
- Brains mentions to Gordon that he has a 'new' Exo Suit in this episode inside Thunderbird 4. However this model of Exo Suit was first seen in Deep Search, worn by Alan when they rescued the Pendergasts, with Alan's red colour variation and the lack of a laser on the right arm. It is likely that this episode (along with Up from the Depths Part 2) was to air after Deep Search.
- In addition, Gordon mentions having broken a ship in City Under the Sea, which may or may not have been Thunderbird 4. If it was, the Up from the Depths story must have been intended to serve as the Mechanic's second appearance
- TV-21's control panel looks similar to Thunderbird 3's in the original series, while the pilot's seat bears resemblance to the one in Thunderbird 1's cockpit.
- When Gordon enters the cockpit of the TV-21, a rendition of the original series' "Thunderbirds March" theme can be heard.
- The Ray-Mechas the Mechanic deploys make different sounds when destroyed to the ones in City Under the Sea.
- When Lady Penelope and Parker infiltrate the shed where the Mechanic is hiding his equipment, Sherbet gets outside the car too quickly.
- Virgil suggests sending down a Pod vehicle. However, Module 4 wasn't shown to have the capability to build pods until Power Play. It has to be thought that they used the Remote Airbag Pods used in Heist Society.
- In the scene where The Mechanic is shown tracking Tracy Island there is a hologram with Thunderbird 3 launch bay being closed. It is only closed when Thunderbird 3 is on a mission, but Alan was seen in the scene after that at the Holotable.