While on the Justice League's orbiting Watchtower, an alert of dual
emergencies in Gotham City calls Batgirl and Supergirl into action. They
step into the teleporter. In the same moment, something attacks and
damages the Watchtower's tech. The two girls return to Earth... but as
one combined Super Hero! As they try to undo the mashup mishap, the
merged pair also need to stop Two-Face's double-trouble crime spree
that's wreaking havoc on the city. Can the two friends work through the
fusion confusion and fight as one? Find out in this action-packed,
illustrated chapter book that's perfect for young DC Super Hero fans!