When a junkmail robot invades the TARDIS, the Doctor gets led down an unnervingly familiar path. Meanwhile, space beatniks Kingpin and Juniper Berry just want to hitch rides and busk - until a greater purpose calls. The Doctor's past and Kingpin's future are entangled by malevolent forces. The Psychic Circus is just beginning: it may bring back clowns, but it already has a Master....