What would the police do in this situation?

I'm not sure how things are done in the show me state but in many states the law sides with the mother in situations involving children, the police should call you to confirm whether or not the father could take the children. You should contact an/your attorney and consult with him/her on this matter. You can also call your local DA's office and ask questions about that too.

Hope this helps, good luck

The children would have to be leased into the custody of their legal guardian. The cops would have no joice than to give the kids back to the husband, unless seen as unfit to care for children

i would think the father has more right to take the kids then the grand parents do to not release them to him unless there is a court order that says you have full custody and that he can only take them when you say then the cops would make him leave and not return until then i am pretty sure your parents are forced to let him see them and take them

Since there is no custody order, the father is as much a custodial parent as you are. As such, he can take the children any time he wants, and if your parents refuse, they can be arrested for custodial interference or even kidnapping.

Temporary/Emergency custody orders are possible.