Ep 20. Hook, Line and Sinker

In the season 1 episode 20 of H2O titled "Hook, Line and Sinker," the three mermaids Emma, Cleo, and Rikki find themselves in a predicament when a fishing net traps them underwater. As they struggle to free themselves, they realize that they cannot use their powers as the moon is not in the right phase. But things get worse as the fishing boat begins to reel them in, and they are forced to use their combined strength to resist being caught.

Meanwhile, Lewis and Zane are competing in a fishing competition, with Lewis determined to beat Zane, who is known for his successful fishing endeavors. However, their rivalry is taken to a whole new level when Lewis accuses Zane of cheating. Zane denies it, but Lewis is convinced that something fishy is going on.

Back underwater, the mermaids manage to break free from the net, but they are not out of danger yet. They discover that they have accidentally ingested a toxin from the net, which is making them feel weak and uncoordinated. As they struggle to swim back to shore, they become aware of the danger they are in and the threat to their dual identities as human and mermaid.

The situation becomes more complicated when they realize that the fishing boat belongs to Zane's father, who is conducting illegal fishing activities in the bay. Emma, Cleo, and Rikki are torn between exposing the illegal activities and protecting their secret as mermaids. However, they know that the toxins in their system will prevent them from using their powers, putting them at a disadvantage.

As Lewis and Zane continue to argue, the mermaids come up with a plan to sabotage the illegal fishing operation. They enlist the help of Lewis to create a fake Stingray breeding ground that will attract the fishermen's attention away from the real one. With some quick thinking and clever maneuvering, they manage to succeed in their plan and expose the illegal activities.

In the end, the mermaids recover from the toxin ingestion and regain their powers. Lewis manages to catch a huge fish and win the fishing competition, while Zane learns a valuable lesson about the consequences of cheating. The episode ends with the girls content that they were able to protect their secret while still exposing the illegal activities in the bay.