Maggie was Martin Wells' pet dog when he was a child.
One night, Maggie escaped into the woods. Her owner went after her alone, calling her name while searching the area. Before he found his dog, Martin heard a strange noise coming from behind a ridge. He followed the noise to a landing party of Vulcans on a mission to Earth and was traumatized by his experience with them. (PIC: "Mercy")
This character was only mentioned in dialogue.