Attacked by a giant tentacle monster in the tunnels Eli and Trixie try to use their new slug, only to discover Uni has some of the most amazing battle moves they’ve ever seen! But they quickly learn it comes with disastrous consequences to their own slugs’ powers.

With their own slugs now unable to transform Eli and Trixie struggle to figure out the new slug’s powers. They seem to change at random, which is making it tough to battle off the monster stalking them through the abandoned tunnels.

The unruly little neo-protoform slugs have wandered off into the woods all alone. Worried they’re lost and helpless, Trixie sets out to find them - until she ends up needing her own rescue party.