"Infinity Beach" is the second McDevitt I've read, after the excellent "Moonfall." Whereas "Moonfall" had me hooked from the get-go, this took a bit more reading before I really got into it.
The set up is slow, almost glacial, but he teases you just enough to keep you interested. Sometime about 1/4 of the way in all the pieces start to get intriguing. By the time our protagonist sets off to Orion's belt to further investigate, you're in for the long haul. From there, things start to accelerate and a book that started out as "I guess I can read a few more pages..." becomes one you can't put down.
"Moonfall" is better overall, but this is a better story and a more interesting resolution.