The Sixth Doctor returns, and he's thrown straight in at the deep end! Travelling the galaxy with Melanie Bush and their brand-new companion, marine biologist Hebe Harrison, there are wonders to see, dangers to face and plenty of peril beneath the waves. Ep 1 - The Rotting Deep by Jacqueline Rayner (2 parts). A mysterious SOS summons the Doctor and Mel to an oil rig in the North Sea where a dwindling group of survivors awaits rescue from a lethal menace, One of their number is Hebe Harrison, a wheelchair-using marine biologist who is definitely more than she seems. Can our heroes escape the rig? And just what is killing off the rig's beleaguered crew? Ep 2 - The Tides of the Moon by Joshua Pruett (2 parts). For Hebe's first trip in the TARDIS, the Doctor and Mel take her to the nearest available 'water world' - the Moon, two billion years in the past! Its advanced humanoid inhabitants, the Gilleans, are terrorised each night by their monstrous enemies, the Sheega. Even more worrying is that in a matter of hours, this ocean world will be laid waste by the gravitational interference of the blue-green planet next door... Ep 3 - Maelstrom by Jonathan Morris (2 parts). The Doctor, Mel and Hebe visit the archipelago world of Veludia, only to discover a planet beset by electromagnetic storms where three survivors traverse the seas in a ramshackle township. These survivors are 'corps' - bodies used as hosts for minds stored in the vessel's 'mind-drive' - and the Doctor, Mel and Hebe are seen as welcome replacements. But there's something lurking in the waters below, something of rage and power that wishes to destroy them all: the Maelstrom! CAST: Colin Baker (The Doctor), Bonnie Langford (Melanie Bush/Alef), Ruth Madeley (Hebe Harrison), Amerjit Deu (Jom), Kim Durham (Vale), Virge Gilchrist (Hellas), Cherylee Houston (Elise), Nimmy March (Mada/Saskar/Alef), Rove McManus (Jonah Strong), James Smillie (A.M. ‘Ancient Mariner’), Andrew James Spooner (The Clutch Father), Sam Stafford (Wulk), Mandi Symonds (Skye Bennet), Charlie Tighe (Carl Price/Dean). Other parts played by members of the cast.