Do the job...

You slide into an alleyway and look in the briefcase. You find the first half of your pay as promised, a fake credstick (id/credit card), and a key.

You smile and close the briefcase, taking out the credstick and the key and putting them in your jacket pocket. You head to your apartment and set down the briefcase on your table. You slip the credstick into your home computer and read the ID, today you are Jack Messinger, you have 500 nuyen (dollars, if you like) that WILL be taken out of your own real funds if you have to use any under your alias.

Getting the plan together, you head out to the mark's house.