The ship is soon infiltrated by a , a tiny, indestructible alien that consumes non-organic matter, including the ship's internal systems and energy sources. The situation becomes a "conundrum" when the Doctor realizes that if the Pting damages the ship's power source, the remote station will remotely detonate the Tsuranga to prevent a catastrophic explosion. The Doctor eventually defeats the creature by "feeding" it a bomb intended to destroy the ship, utilizing its high energy to satisfy the Pting's hunger before ejecting it into space. Cast and Key Characters
: Jodie Whittaker as the Doctor , Mandip Gill as Yaz , Tosin Cole as Ryan , and Bradley Walsh as Graham . [S11E5] The Tsuranga Conundrum
: The lead medic who is killed early on while trying to contain the Pting. The ship is soon infiltrated by a ,