As they return to the school, a chance remark by Watson causes Holmes to realize that Eh-Tar is none other than Professor Rathe, but he and Watson arrive too late to stop him and the school nurse Mrs Dribb, who is revealed to be Eh-Tar's sister, from abducting Elizabeth. Using Waxflatter's latest invention, a flying machine, Holmes and Watson travel to the warehouse just in time to prevent Eh-Tar from sacrificing Elizabeth as the fifth and final "princess". They accidentally burn down the Rame Tep pyramid, killing several cult members, and Mrs. Dribb is shot through her own blowpipe. Eh-Tar escapes with Elizabeth and confronts Holmes on the frozen Thames river. Eh-Tar tries to shoot Holmes but Elizabeth shields him with her body. Holmes and Eh-Tar duel and Eh-Tar falls through the ice into the river, apparently dying. A grief stricken Holmes cradles Elizabeth as she dies.