Re: Osgood is back !
"My thought is that Missy's ray gun thingy wasn't the death ray we all thought it was. After all, it didn't kill Missy, why would it kill anyone else?"
Missy's ray gun thingy was never fired at her - the Cyber Brigadier shot at Missy. Missy didn't die because she was wearing a Vortex Manipulator that she had rewired to work off of death ray energy, as explained in The Witch's Familiar. However the still-alive Osgood is explained, Zygons are involved either way.