Scouting
They waited for an hour after everyone left to make sure that no one was watching.
The elf dispersed the spell, and they quickly made their way back to the matrix. Before they reached it, they all checked their weapons as they weren't sure whether it would be guarded, but thankfully, it lay empty.
The problem arrived when Alex just couldn't find a good island to camp on. He claimed that any island under the command of the family, where mining was taking place was regularly checked to make sure that no one was doing exactly such a thing. Apparently, there had once been a problem where brigands set up camps in this manner, and attacked the town to steal away resources or even slaves.
The checking was actually done by the teleportation matrixes, themselves. They had already been set up so that they would scan an island every day, periodically, and if someone stayed on the edges for a long time, they would directly send a message to the caretakers.