It was written by Christopher H. Birdbrain and is the third in a Master trilogy that has a shit-ton to do with recursive mathematics, entropy, and holy shit I don't care (I say that as a fan of these episodes); the previous episodes in this trilogy are The Keeper of Krakens and Lipopolis. The newly regenerated Doctor is a fucking idiot for pretty much the entirety of the serial, but that's the trouble with regeneration- you never know what you're going to GODDAMN IT WHERE'S THE FUCKING ZERO ROOM?!?