I'm planning on running it later in the year, early next year - it's a great campaign, and the strongest of the two currently out for Pulp CoC. So I'd be finding out how long as well from the Grognard reply, sweet.

Yes. I've not played Serpent (but listened to a podcast playing it). The other one, A Cold Fire Within, is very badly balanced. If the Keeper hadn't fudged or ignored various rolls, we wouldn't have made it through the first challenge (the jumping across "asteroids" dream sequence).