A rogue Dragon Rider aboard a heretofore unseen Razorwhip starts attacking ships. Hiccup and his team investigate. Almost completely bested by this attacker, the Dragon Riders finally unmask the rider as the familiar Heather. Their renewed acquaintance is a generally happy one, but why she's out attacking ships is information she's quite unwilling to share, so Hiccup investigates on his own.
—statmanjeff