Take a look at the passage again:
Bored with the revision of his research essay. Patrick poked the soft front
of his flat-screen monitor, fascinated by its squishy surface.
You chose to connect the participle phrase to the main clause that follows, like this:
Bored with the revision of his research essay Patrick
poked the soft front of his flat-screen monitor, fascinated by its squishy
surface.
Unfortunately, removing the period alone will not do the trick. Review the rules.
Go back to the sentence to try again.