Back in London, Glendon is visited by the enigmatic Dr.
Botanist Wilfred Glendon (Henry Hull) travels to Tibet in search of a rare flower, the "Marifasa Lupina," which blooms only in moonlight. Glendon scoffs at Yogami's stories, until the next full moon!. Yogami (Warner Oland), who tells him a current rash of murders is the work of two werewolves. Despite warnings that the region is dangerous, Glendon continues his quest until finally locating the exotic flower, but not before he has to defend himself from an attack by a howling monster.