Ep 6. Thunderbirds Are Go: S3 E6 - Up From The Depths, Part 1

Thunderbirds Are Go: S3 E6 - Up From The Depths, Part 1 follows the adventures of International Rescue, a secret organization led by Jeff Tracy and his sons. In this episode, a massive underwater mining machine called the Haynesville is suddenly reported missing, and International Rescue is called upon to investigate. Upon arriving at the site, they discover a massive hole in the sea bed, leading to a vast network of underground tunnels.

As the team investigates, they encounter a new threat, as well as an old enemy: the Mechanic, who was previously thought to be dead. The Mechanic has returned, and he's as determined as ever to destroy International Rescue. He's been using his skills to build a new machine, which he intends to use to take over the world.

Meanwhile, Lady Penelope and Parker are investigating a series of thefts at the Louvre Museum in Paris. They discover that someone is stealing ancient relics, and that the thief may be connected to the disappearance of the Haynesville. Lady Penelope and Parker set out to gather more information, but they soon find themselves in danger, as the thief is not someone to be trifled with.

Back at the site of the Haynesville's disappearance, International Rescue discovers that the mine was built on top of an ancient structure, which is now being used as a base by the Mechanic. The team descends into the structure, where they encounter a complex maze of tunnels and chambers, filled with traps and dangers.

In the underground base, International Rescue discovers that the Mechanic is creating a massive, spider-like robot kaiju, which he plans to use to wreak havoc on the world. The team also learns that the Haynesville was destroyed because it uncovered the Mechanic's secret lair.

The episode ends on a cliffhanger, with International Rescue trapped in the underground base, and the Mechanic's kaiju almost completed. The team must find a way to escape and stop the Mechanic before it's too late.