The best of the three-module Lost Tombs set. The DM is provided with a wide selection of puzzles, riddles and combat encounters, so many in fact that less than half will probably be used, leaving the remainder available for use in other scenarios. A few of the puzzles and riddles are of the groaner type as in "who's buried in Grant's Tomb?" and the algebra problems get somewhat repetitive, but overall I thought they were fairly entertaining and quite a bit different from the usual chestnuts that pass for riddles or puzzles in published scenarios. Hack and slashers need not despair, there are plenty of combat areas and failure to figure out the puzzles in time usually results in a fight as well.
Most of the encounters have some Greyhawk "flavor" added to them and Reynolds cleverly includes a few encounters that utilize scenes from the classic Greyhawk modules of yesteryear. The Greyhawk references are certainly not overwhelming, however, and a real strength of the adventure is that it could easily be adapted to any other campaign.
There are a few Greyhawk timeline errors in the background information, but nothing fatal. If the writing has any real faults, it might be an overdependence on overwhelming magical coercion of the PCs and tacky plot devices that rely on magical means to attain mundane result. Both methods smack a little too much of that other (ick) campaign world where wizards routinely waste telekinesis spells on fetching themselves a mug of beer from ten feet away. These are certainly minor quibbles, the Crypt of Lyzandred the Mad should prove useful and amusing for GMs in any campaign.