Take a look at the passage again:
To make Sylvia, the party's hostess, happy. Kelvin steeled himself, dipped
his spoon into the squid eyeball stew, and began to drain the bowl.
You chose to connect the infinitive phrase to the main clause that follows, like this:
To make Sylvia, the party's hostess, happy Kelvin
steeled himself, dipped his spoon into the squid eyeball stew, and began
to drain the bowl.
Unfortunately, you must do more than remove the period after happy. Review the rules.
Go back to the sentence to try again.