I made the mistake of parking Bloodscythe and Soulrender--the Deathbrand scimitars--on my bed while I went out for a short quest. They had been rolling around of their own volition when I left (which should have been a hint to me). When I got back, Bloodscythe was MIA and I couldn't locate it anywhere. Soulrender I've put in a weapon rack. I also had an enchanted dagger go missing when I dropped it near the Blacksmith's worktable. WTF...

have you considered storing them in a container rather than out in the open?

They probably fell through the ground, it happens to items all the time, especially if you run into them and make them go flying. If they were rolling around, good chance they fell through the ground somewhere.

Reload a save before you saw them rolling all over?

I put the surviving sword in the weapon rack next to the mannikin that holds the Deathbrand armor set. I'm thinking the MIA sword is lost and gone forever, and yes, I should have put them in the rack before I left.

I fell through the ground in Windhelm once. I guess I just have to wait until Raven Rock / my house glitches like that, and then I'll retrieve my lost stuff.

If you're on PC, console them in.

Too late now. I delete old saves when I get about 70 of them. Mea culpa.

Eh, don't delete. Copy them to a separate save location - external drive, secondary hdd, whatever....

They may still be in your Recycle Bin. It's worth taking a look.

It's still "Strange things were afoot at the Circle-K". I got 3 Dibella statues from the Rieklings, put them on the bed, and they wound up on the floor. The garments of the 2 slain Severin women I was going to sell, but they're moving around as well. The Dunmer Outfit of Jirri has a blue glow to it. I put that item and the mother's (if indeed she was Jirri's mother) Fine Clothes on the table upstairs, and the Fine Clothes wound up on the floor. Plus 2 of the skulls in the display case aren't selectable. The other 3 were.

Odd stuff.

Look up their i.d.'s on the wiki and console them to the player

prid

moveto player

if they're still in the cell somewhere they should show up

I'm thinking Item Migration is maybe a function of how the game places stuff when it loads. What comes to mind is seeing things like a Mammoth and a Solitude Guard drop from the sky during a Wait. I'm on an Xbox 360. The blue glow from Jirri's Dunmer outfit might mean she was a Mage? No apparent enchantment on it. Can't remember what sorts of combat were being used by the two of them in the melee, but I heard Jirri say, "It's not my time" as she died.

Whatever.

Looks like all of the Dunmer Outfits have that blue glow.