If you choose the Revenge deal, the rich old man you helped (whose name you forgot) will drive by your cousin's wedding and off with Kate. After a day, Little Jacob calls you with a lead to where Jimmy is hiding. It took forever for me to beat this due to a glitch when Niko had to climb into the chopper
https://youtu.be/DEY3aLxobh8?si=vuuQ_yPNQ_NvC_jO