For example, when Jack and Will reach the Isla de Muerta, Jack is getting ready to use Will – whose blood is needed to break the curse – as a bargaining chip to reclaim the Pearl. Will – who knows Jack intends to use him as leverage – now has the opportunity to rescue Elizabeth and no longer needs Jack’s aid, so he abandons Jack to Barbossa and his crew. Similarly, at the end of the film, Jack strikes a bargain with Barbossa that would give Barbossa a grander ship to command, allowing Jack to once again captain the Pearl, yet reclaiming the Pearl is only half of Jack’s ultimate goal; the deal was really made to allow Jack the opportunity to take revenge on Barbossa by removing his crew from the equation. here