[s1e11] Boom Town -

The Doctor, Rose, and Captain Jack Harkness stop in modern-day Cardiff to recharge the TARDIS at a "rift" in space and time. While there, they discover that a (an alien from the planet Raxacoricofallapatorius) has survived their previous encounter in London.

Watch a reaction to the iconic Ninth Doctor episode, including thoughts on the Slitheen's return and the ongoing Bad Wolf mystery: [S1E11] Boom Town

: The phrase "Bad Wolf" appears again in this episode—specifically as the name of the power station project ("Blaidd Drwg" in Welsh)—furthering the season's overarching mystery. The Doctor, Rose, and Captain Jack Harkness stop

: The TARDIS "judges" the Slitheen. When she looks into the heart of the TARDIS (the Time Vortex), it reverts her to an egg, giving her a chance for a fresh start at life. : The TARDIS "judges" the Slitheen

Disguised as a human politician named Margaret Blaine, the Slitheen has become the . She plans to build a nuclear power station directly on top of the Cardiff Rift. Her true goal isn't clean energy; she intends to trigger a meltdown that will destroy the Earth, using the resulting energy to power an "extrapolator" to fly herself home. Key Themes & Moments