After a little research, I learned how to fish the Mouse Pattern:

Good casting skill is needed to present a mouse 60 feet away from a boat.
The presentation of the mouse must be done so as to resemble one that came
to the water's edge and accidentally fell in. The cast is made so that the
mouse lands on or bounces off the rocks. When the mouse lands on a rock, a
small twitch will cause it to fall in.

Getting the mouse there isn't enough. Brown trout like mice but rise for
them slowly. The trout knows a mouse in the water is in trouble and doesn't
have to hurry to eat it. He'll swim from under a rock ledge or shadowed
shoreline and slowly rise to feed. While the trout is deciding whether or
not to eat the mouse, the imitation must act like it is swimming and
struggling to get back to safety. Even then, mice swim slowly. So line
stripping (pulling line in for non fly-fishers) is done only an inch or two
at a time with a slight twitch. Swim the mouse too fast and the trout will
realize something's wrong and won't take it.

Trout first pull a mouse down by the tail to drown it. That means the hook
shouldn't be set on the first tug, to do so will pull the mouse from the
fish's mouth. Wait another moment or so, allowing the trout to take the
entire mouse in its mouth before striking. But don't wait too long! The
trout will realize the mouse is a fake and spit it out. There's a split
second when the trout bites the mouse by the tail and another split second
when the trout gets the whole mouse in its mouth. That's when the hook must
be set. Remember, the trout's mouth is hard and bony, so the hook must be
sharp and set crisply.

-tom