Ran an island with several friends. After a couple of islands, we got Molten Clay. We killed the % necessary for the elites to spawn on the island, along with the portal. 2 out of 3 of us entered in to the portal, proceeded to kill the elite mob, within, however had no portal back. Thankfully we were in discord with the other remaining member of our team and informed him, and he carried on killing until the bar was filled and we could leave. We searched high and low for a way back but could not find it.