In the Mako Mermaids Season 1 episode " Nowhere to Hide ," the mermaids try to secure a dangerous, ancient merman trident that Zac has hidden at a fish packing warehouse. As the threat of the artifact being brought to the Moon Pool grows, the mermaids must stop Zac from causing a catastrophe. You can watch this episode on IMDb or read about it on Fandom .
Watch clips and summaries of this pivotal episode to see the mermaids' struggle against the Trident: [S1E20] Nowhere to Hide