umm not a published adventure but i ran this skirmish a few weeks ago for a guy(redneck) who was playing the game for the first time.
town of sandybrook medium sized city by a river. fill out town to taste, there is a monastery in the hills outside of the town.
bulletin board or gossip or town guard, will let the adventurers know whats going on.
farmer is having problems with wolves attacking his sheep wanting some help protecting them. 5 gold per pelt.
innkeeper has heard noises coming from his cellar but with his injury from the war he cant take down the rats. 100g for anyone willing to help(if they go for this instead of rats it is a zombie/ghoul.) a hole in the far wall reveals a tunnel with a small treasure chest.
the monastery has sent a call for help in their catacombs there has been heard terrible noises. (the interred have began raising as mindless undead) further clearing reveals a lich has set up shop deep in the catacombs. (in my adventure the lich was absent at the time. both because of the low lvl of party members, inexperience of two players and the fact it sets up a returning bad guy thats out for revenge.)
hidden study with verious things including a picture of a small rowboat on a storm tossed harbor(this painting is actually a hidden dimensional door lich keeps his phylactory hidden on the boat.)(my guys ended up burning the painting btw) a second hidden panel revealed a +1 longsword, along with verious other random loot and quest rewards.
set up of catacombs was a hallway with door to the northwest side with a corpse of monk that had been eaten to show there were corpse eaters. south end of hallway split into two going east and west each with a locked door. these went to where the bodies were laid the west opened into another room with an alter desecrated by lich and the hidden doors.
east door opened up to a room where floor would be triggered to open slowly into a pit trap falling 30 foot. one of the burrial niches had the triggering mechanism hidden(dc 10) slightly made obvious on purpose to trick people into pushing it. a trap to remove would be grave robbers.
that was as far as we got for the night. if lich was gone can as i said have him be the recurring BBeG mastermind villain after revenge furthering your story
also i kept the zombies fairly weak- imo zombies are strong due to over whelmiong numbers the small amount that had been turned were small fry give them minimum health according to your kids levels. not too hard but not steam rollable