That sounds like a great idea Piratecat. Do you have any suggestions as to what sort of scenario would work well with 2 players? Do you agree that it should be exploring an enclosed environment/resource management theme?
Thanks for your advice so far!
Zombie apocalypse seems like a self-sustaining format.
Whenever things quiet down, zombies show up.
If the party has weak shelter, only one or two show up and start breaking through.
If the party has strong/fortified shelter, it's a a horde of zombies, which will start breaking through the defenses
In either case, odds are good the shelter is compromised and the party must escape
The party will escape to some new shelter generally (or vehicle)
From there, you'll need resource scarcity. When things slow down, the party should develop a need for something they don't already have. Anti-biotics, regular prescriptive medicine (heart, asthma, etc), food, ammo, fuel. The party will form a plan to go out and get some, which of course encounters zombies on the way or while gathering or on the way back.
Both of these types of events are instigators. If things get slow or stable, introduce zombie assault or resource need and that'll get things going.
If the players are busy talking, debating, taking action, you probably don't need to do anything until a disucssion gets too heated or starts repeating itself and not going anywhere.