When a weird, wild wail echoes from the Metropolis Museum, Batgirl and Supergirl rush inside ready for a fight. But all they discover are groggy workers and one ancient tome missing from a rare book exhibit. A moment later, they’re called to a break-in at S.T.A.R. Labs and find... Silver Banshee! The supernatural Super-Villain is scheming to broadcast a mind-control curse over the city! Batgirl and Supergirl are determined to stop the plot, but their foe’s deadly scream makes it nearly impossible to face her head-on. Can the two friends concoct a way to silence Silver Banshee and her spell before midnight? Find out in this action-packed, illustrated chapter book that’s perfect for young DC Super Hero fans! Part of the The Adventures of Batgirl and Supergirl series.