"Here lies a peasant child scarred by the heat of battle.
Fighting not for glory but because he just wanted to live,
His despairation led him to victory."
~ Carved on the ornate stone doors leading to the large tomb.
Historically, most tombs known to have grave goods in them were robbed soon after the dead person was laid to rest. So why has the tomb that your group of adventurers broken into not already suffered this fate?
When running a new party, get around the question of plot density by having the first discovery to be a deck of fate, or whatever you call it. If you use a real deck, you should definitely stack it to have the desired outcome, which is to curse the party to attract weird things to happen and involve them. This should not be told to the players at the time, so that they won't just up and try to get themselves 'decursed'. Though quite why they would want to is beyond me.