So you've been kidnapped or are being held hostage but can reach a family member on the phone.
What secret question or code have you agreed with your family?
Ours is to ask after Aunty Shirley.
Although why a kidnapper would actually allow us access to a phone is anyone's guess.
When the DC's (all grown up), are out late, I might text them and ask 'tell me something your kidnapper wouldn't know' and get a stream of texts of names of family pets 