Two beings from another world wish they were back there, because they make terrible babysitters! 
I mean, seriously! Here they are, exiled from their own world, stuck here in present-day Earth. KNOWING any day, the hunters looking for them will eventually drop in unannounced, and what do these exiles do? They let a couple of kids get caught instead and transported to THEIR world of Dal Ryeas!
So now, they have to take the spoiled 18-year-old girl still left with them BACK to Dal Ryeas to rescue the other kids! And THAT won't be a fun task because these kids are actually quite useful to BOTH SIDES of an ongoing civil war of sorcery and domination! 
You want to talk about sibling rivalries...? 
Read on! 