Luckily we called for the animal ambulance to tell them about it, and in the afternoon they called us back saying there was a marter spotted 2 streets from ours, sleeping in a bag of sawstuff (or whatever it's called in english)
We both already guessed it would be our ferret, and went there. Well, the people there, as simpleminded as they were, were very afraid of it, we just picked it up and walked off with it.
Yeah, my mom was so uberhappy and I was all cool and half emotionless there, carrying the ferret. xD
Anyhow, it's all safe, I'm glad we didn't lose 'em, not that we probably would, as they're good survivors, even for tame animals.