What deal does viola make with the captain?

In Shakespeare's "Twelfth Night," Viola makes a deal with the captain who rescues her after the shipwreck. She asks him to help her disguise herself as a young man named Cesario, which involves cutting her hair and dressing in male attire. In exchange, she promises to reward the captain for his assistance and loyalty, setting the stage for her adventures in Illyria. This deal is pivotal as it allows her to navigate the complexities of love and identity throughout the play.