In "Doctor Who" season 2 episode 3, aka "The Well", the Doctor's quest to return Belinda Chandra to Earth on May 24, 2025, takes a detour to a dead world hundreds of thousands of years in the future.

"The Well" saw Doctor Who give a David Tennant episode a surprising sequel that may have hinted at the schemes of a greater villain in Season 2.

In the 15 episodes that comprise the Disney+ era of Doctor Who to date, we’ve seen a marked absence of the more familiar returning foes. No Daleks, no Cybermen, no Master.