Thank you so much for suggesting putting out something that smells like home. I put out a throw pillow with a pair of my socks on it before going to bed and when I checked at 3:30 this morning – there she was. Being that Dolly is a rescue dog and that we have only had her for one week, she is still very shy and hasn’t really had time to bond with us yet but we will persevere and eventually gain her complete trust.
A happy ending! Linus showed up late last evening. As per your suggestion, we had gone out again in the dark looking and calling, and he appeared about 40 minutes later, looking absolutely fine. We suspect he was locked in somewhere, as he is not inclined to leave the yard.
Thank you for your help, and thank you for offering this service. It is an invaluable service for pet owners.