When Q triggered the watch, it broke the paralysis spell and disoriented Martin. That's why Kady was able to hit him with magic and Alice could push him back through the mirror. He could fight them but not them + watch magic.

I'm hoping based on season 1 that there's basically a split to the series: defeat the beast (hopefully early in the season), then do a saving Fillory plot for the remainder.

I wonder how many of those times he came to the same conclusion.