Okay! Here is the outline of my idea, you know, the one that has 0.0% chance of actually being made into an official D&D movie.
In a mid-sized fantasy medieval town a mysterious sickness starts to spread, mostly affecting the young and the infirm. Our protagonist is a thirty-something single mom who once had a promising future as the apprentice to a scholar and a wizard. Now she does other, less exciting stuff. And naturally her daughter comes down with this sickness. Now, not being the ignorant sort, she looks through some old books she read back in the day looking for a half-remembered legend about a Healing MacGuffin in the Local Dungeon which is definitely NOT a mere legend and is well known to be extremely dangerous, particularly in the last couple of decades.
Of course, it has been a long time since our protagonist has had anything resembling a disposable income, so she seeks help from the local wealthy baron, in this case a somewhat eccentric goblin alchemist by the name of Slurg von Slurg. The story is that he came to his position through being adopted by the previous baron as a tiny goblin baby and raised to be "civilized" and "proper" . Slurg shows great interest in the Healing MacGuffin and immediately promises to fund a small group to enter the Dungeon and attempt to retrieve the MacGuffin.
In need of allies, the protagonist heads to a tavern on the far side of town which has been cordoned off from anyone showing signs of the sickness and is serving as the sort of base of operations for the townsfolk who are still well and in charge. She enlists three allies:
A female dwarven rogue who has experience with the Dungeon. In fact, while she does not tell anyone else about it, she actually has something she wants to put back that she and her friends took from it a long time ago. She has reason to believe this particular something was special and not a reason to inhibit other recreational looting. Definitely has nothing to do with the increase in activity from the Dungeon in recent years, amirite?
A male elven elf. Yes, you read that right, : ) . I joke, but I am referring to the old school elves that were basically fighter/mages. This is the guy who has been around the block, forgotten most of the skeezy things he did on the block, and then went around the block a couple more times before deciding he was tired of running away from his mistakes and that it is time to take some responsibility. Also important to the "training montage" where our protagonist gets back into spell-flinging shape.
A male half-orc warrior, and general Slurg fan boy. The guy who has struggled with his mixed identity and looks up to the goblin lord who became respectable in the society of more generous races. Will become more popular in the second half of the film.
The heroes have a few days to gear up and prepare. The protagonist, with the help of the elf, tries to reabsorb the lessons of her youth so that she can lend some magical firepower and some general knowledge of fauna and flora as well. The daughter is obviously getting less well fast, as is everyone else, ramping up the pressure.
I have no really brainstormed what actually happens on the expedition. Obviously it is an important part of the film to get the Dungeon right, but the specifics are not really central to my idea. It should probably have a dragon though. At least a dragon idol. Maybe the dwarf pried something off a dragon statue (as opposed to an efreet statue) or altar. Or maybe a small dragon should appear. Nothing so big to quite scream "raze the town faster than the plague will" though.
Anyway, so the heroes get the MacGuffin, maybe the elf dies in the interim, and the rest head back to town. They go to Slurg von Slurg to consult on how to make use of the MacGuffin, and that is when he springs his untimely but inevitable betrayal. Slurg used his alchemy to cause the plague, and he agreed to bankroll the expedition so that he could get his hands on the MacGuffin and prevent its use to save the town.
As I mentioned before, Slurg von Slurg was adopted as a baby goblin, the son of a slain goblin chieftain. What went unmentioned is that not only were his parents dead but so was his entire tribe, killed by a war party lead by his adoptive father to destroy the goblins for their capricious attacks on the townsfolk. He is eponymous child spared the sword, except in this case his rage and thirst for revenge was fueled by the fact that he was the only goblin child spared, more out of his new "parents" desire to make an example of giving him a different upbringing rather than genuine mercy. Because everyone else was slaughtered. This sickness is his revenge, targeting the children of the town, along with the elderly, as his hate fueled judgment.
I am not certain what form the physical resolution of the plot takes, but the betrayal fuels the major character arc of the half-orc who eventually figures out what his path in life must be. The final battle pits Slurg's potion based magic against the protagonists ability to make clever use of a rather truncated selection of spells. The MacGuffin is recovered, and utilized to cure the plague. Maybe in the last pre-credits scene a real dragon shows up and demands the MacGuffin for its horde, setting up the antagonist or at least one of the players of a possible second film.
