***CONTENT WARNING: LANGUAGE, VIOLENCE, GORE***
Serenity and her group were on the southwest side, at the base of the Selkies' island when they had realized that they were being watched. She had felt eyes on them since they had left the Mosasaur's old den, but she didn't see anyone along the way.
The moment that they had left Nereus' Cradle, their group of thirty or so had been watched and followed by several Sirens. They had originally been tasked with monitoring the Selkies' movements, but Medeva had told them to kill anyone they saw with the Undine Queen. In case the guards on the mountain top had failed.
There were as many Sirens as there were Aquarians with the Undine Queen, making victory nearly impossible without starting off with a surprise attack. Serenity's group gave no signs they knew that they were being tracked. So the Sirens thought that they already had the advantage.