It's supposed to be on the outer casing (according to the shimano manual) but the Tricross has internal cable routing.
Anyone know where it is? I really don't see it but I might be being a bit simple.
With out a photo it is hard to tell. Jagwire does make inline adjusters. They have different types, that adjust differently. Check the Jagwire website or ask at the LBS where you got the bike for assistance.