raids on the Aegean islands end early

My raids on the minotaur islands are ending before the time is up. This is on the 4th island. 

Thanks

you must spend gems ?

Hello there,

This is more likely because you used Ariadne’s Spindle.

Your Units appeared directly at the location of the portal, and some enemies might have been left behind, and reached your Olympus Portal without being attacked by your units in the meantime.

You can see if your Olympus Portal is under attack when a blue bar appears at the left of your screen, with the icon of the portal.

Be careful when using Ariadne’s Spindle, this is a really powerful power, but if you don’t pay enough attention you can be placed in a delicate position very easily.