Corn Husk Thief

Varden knows some local Nexus gossip that the others have not been exposed to. Recently, there have been persistent rumors of a series of mysterious thefts over the past few months. Thefts in Nexus are fairly standard, but these stand out for four reasons (at least, if you believe the stories; no one official is talking):

the stolen items were all incredibly well secured
the items taken have been eclectic and somewhat worthless while more valuable items have been untouched
some of the items have been returned either to where they were stolen or placed in some other secure spot, and
in each case, the missing item was replaced by an empty corn husk.

Varden normally wouldn't care much about this, except that in one of the cases, he thinks he happened to catch a glimpse of the thief. Out late a week or so ago, you saw an extremely attractive dark-haired woman jump from roof to roof over an alley way, a white-purple hollow circle dully glowing on her forehead. Wanting to talk to her, you gave a brief chase. The chase led down from the rooftops into an alley where, right before your eyes, she seemed to become her own shadow and slip under the crack of a door in front of you. You managed to force the door, which opened into the storage room of a tavern. The woman was gone, with the only other exit being through a door into the tavern which was bolted from the other side.

It wasn't until the next day that Varden heard a rumor that one of the "corn husk thefts" happened just a few blocks down the street where you first saw the woman. Since then, he's heard about at least these thefts (though, again, no one is saying anything official):

On the 2nd Day of Ascending Water (over four months ago), an old, but not particularly valuable book on ancient languages from the inner library of the Nexus Temple of the Immaculate Order. The book appeared on the door step of a local book sellers three days later.
On the 27th Day of Ascending Water (about three months ago), the captain's log and shipping manifest from the Guild cargo ship River's Wake. These were found the next day on the Quartermaster's desk in a cargo warehouse on the river on the other side of town.
On the 18th Day of Resplendent Water (about two months ago), the diary of Chantily Divivich, 15 year-old daughter of Guild Factor Milo Divivitch, from the Divivitch estate. Two weeks later (10th day of Descending Water), while visiting relatives in Great Forks, Chantily woke up to find the diary under her pillow.
On the 1st Day of Ascending Earth (about three weeks ago), an artifact for enhancing sexual prowess from the townhouse of Cynis Janus, a Dragon-Blooded socialite known for holding regular orgies and rumored to be involved with the trafficking in drugs and people. Five "indentured" concubines also went missing. The artifact showed up the next morning in the midst of a horde of fornicating animals in the Coffleblock Market. The concubines have not returned. Of all the thefts, this one received more public scrutiny.
On the 17th day of Asending Earth (about a week ago), the family crest from a shield stored the vault Durmat Varkane, a respected armor merchant. The crest was returned the following night. (This is the theft that Varden thinks he saw.)