Continuing the adventures of Hiccup and his friends from How To Train Your Dragon and the Dragons: Riders of Berk TV show!
"Underworld"
During a routine training exercise, Hiccup and his friends discover a huge, mysterious pit in a forest near Berk... They decide to investigate ... Meanwhile, a number of fishing vessels near Berk have gone missing, so Stoick decides to investigate – and bumps into an old enemy... And just how are Hiccup and Stoick's predicaments linked?