Past takes you to that member's hello card in the previous issue. If that member did not contribute to that particular volume, you can keep going. If you want, you can keep going all the way back to volume 1. At any time you can stop where you are or return back to the very first card you started from. The future button does the same thing in the other direction.

If you stop in a particular volume and you wish to get back to the card you started from, hold down the option key and hit the bent return arrow (this works in all kinds of situations).

With this new feature, hello cards will form a continuous chain stretching from the past into the future. If you want to take a stroll down memory lane, just pop to your hello card and keep going into the past for as long as you want. It would be nice if the future button could display hello cards you haven't written yet, but I'm not that clever.