Alison Brown forwarded me this.
From Canadian Peregrine Foundation FB page-
March 21 at 6:13 PM
DON MILLS : Before the season starts, I just want to say a proper goodbye to another one of our resident peregrines, Mystery. He was a great mate to Quest since 2016. They had 22 successful hatches and fledges (tho some were lost after). He was a great Dad, taught his young well, looked out for them, fed them and was always on the alert! He was famous for his many, many alarm calls, which his young picked up quickly and were known to join in on the calls lol. I loved watching their interactions... He would try so hard to get egg time and then try to look after or feed the kids but Quest would only give him small amounts of time... It was so funny and cute. He will be missed.
But there are posts on the real Peregrine Foundation website with a hint that there is a new man, Quest's son from a couple of broods ago:
http://peregrine-foundation.ca/w/c/sightings/toronto-don-mills/