Features the debut of The Deathly Floor.
The Doctor and Sarah Jane crash land on a planet which has drained all power from the TARDIS. The Daleks show up but the planet drains their power too so they can't use their weapons (til they attach some old-fashioned machine guns and get back to massacring everyone again).
Turns out the power drain is coming from a huge futuristic white city which is full of tests and traps that of course the Doctor has to solve in a race against time with the Daleks.
Bellal is hot.