Adventure race anyone?

It looks like I'll be doing a duo adventure race Sept. 10th over in Lawrence called the Wakarusa A.R. My partner is 1/2 my age.....I hope he can keep up!
The Niner is delivered to its new owner, so I've only been on the road bike/running in preparation for my newest "thing" to do. There will be a total of 7-8 miles of trail running, 17 miles of mtn biking and a 4.5 mile paddle down the river.....always keeping my partner with me. It's a new format for me to grasp. I'm usually trying to drop anyone close. What the heck, it's sounds like fun.
I'll use one of the demo Epics from the shop, because technically, I'm in the market to buy a new bike. What a better way to put a potential bike to the test than race conditions.