During the Second Task of the Triwizard Tournament, the colony consented to hold the hostages that the Champions had to rescue in their village. As part of the agreement, their singing voices were used as part of a clue that the Champions would need to decipher. The Golden egg, which the Champions had to retrieve from a dragon in the First Task, contained a song that could only be heard when submerged underwater.
The Second Task
During the Second Task, the Merpeople attempted to stop Harry Potter from rescuing more than one hostage. After Harry successfully rescued both Ron Weasley and Gabrielle Delacour, the Merchieftaness spoke to Albus Dumbledore about the incident, and recounted his determination to see all the hostages to safety.
Behind the scenes
- In LEGO Harry Potter: Years 1-4, the merpeople actually attack, whereas in the movie and book they only confronted Harry when he tried to take more then his own hostage, but even then they only threatened to attack.