Meanwhile, Lazarus returns to his office with his partner, the elderly Lady Thaw. She insists that she be the next to use the machine so they can be young together, but he refuses. She threatens to have Mr. Saxon pull their funding, but Lazarus transforms into a monster and kills Lady Thaw. The Doctor and Martha discover Lady Thaw's body and deduce that Lazarus must drain life energy to keep his DNA stable. Lazarus attacks the Doctor and Martha, in his alternate form as a giant skeletal scorpion-like being, and they hide in his machine. The Doctor explains that Lazarus' transformation is the result of an evolutionary throwback locked away in dormant genes that the machine unlocked. Lazarus activates his machine, but the Doctor sets the capsule to reflect energy rather than receive it, and Lazarus is blasted away.