So there was a CA custodyr order in place?
In this court order you didn't get summer, but your ex gave it to you anyway?
She probobly filed for an emergency order when you refused to bring the kids back?
Have you contacted the CA CPS about what's been going on?
CPS has been involved before, but they didn't contact you before to have the kids come live with you, even though she had to spend almost a year in jail for something related to child abuse?
How old are the kids?
Bottom line (no matter what the answer is the to above questions) you need to show up for court and produce the kids or you will have a warrant out for your arrest. You should be contacting CA attorneys at this point.
It may have been possible to file an emergency order in WA if CA already issued court orders.
Sounds like a mess.