And this time, it is not a 15-foot, 500-pound sculpture giving us the latest clue, rather a package the artist sent to our station in Denver.
In order to understand the significance, you need to rewind a month.
It was Dec. 13 when we did a story on a random sculpture that showed up on 80-year-old Donna Coughlin's front yard in Boulder.
Coughlin told us about a similar thing that happened back in 1987 when CU master of fine arts student, Mark Guilbeau, put up a sculpture on her lawn overnight, and attached a pair of colorful earrings.
Coughlin found out it was Guilbeau -- they had coffee together -- but then lost touch over the years.
It's unknown if Coughlin's latest sculpture was the work of Guilbeau, but it came with the same type of earrings.
On December 14, the mystery artist had struck again.
This time, the artist erected a sculpture in front of the Boulder History Museum. The sculpture also had earrings attached.
As the intrigue increased in the Boulder area, so did the number of posts on our website reacting to the story.
But then the artist took a holiday break.
Last Wednesday, the artist was at it again, and had sent a package to 9NEWS.
The package was also addressed "in care of" madisonrenee186.
That happens to be a screen name belonging to 25-year-old Madison Upton, of Longmont.
Madison posted the following comment online after one of our stories aired:
Madisonrenee186 wrote: "That's hilarious! I'd love that! Hey artist person, I like earrings too!!"
A novice artist herself, Madison agreed to meet us at the 9NEWS studios for the special delivery.
"Wow!" is all Madison could say when she got her first look at the package.
"It's beautiful," Madison continued.
The thick wood frame has a glass front. Inside of the frame is a square piece of paper depicting 100 unique symbols stenciled with what appears to be lead.
To the right of the drawings is a man pointing and talking about the sculpture.
It's possible the artist was giving a playful depiction of 9NEWS Reporter Eric Kahnert, who covered the story extensively when the sculptures were appearing in Boulder.
It's obvious the mystery artist has been following the 9NEWS coverage of their sculpture droppings because that's how they located a post by madisonrenee186.
"So you don't know why he picked you?" Kahnert asked Madison.
"No, I don't," Madison replied.
"Maybe he was just trying to be a nice guy and thought you needed a pair of earrings," Kahnert suggested.
"Well, I love it, I really do," Madison said with a smile on her face.
The return address on the package belongs to a 72 year-old woman in Louisiana who hasn't returned our calls.
However, the postage shows the package was actually mailed from Abita Springs, Louisiana.
According to a public records search, there is a Mark Guilbeau who has a P.O. Box in that city, but no phone number is listed with the information.
"I feel like I'm a 9-year-old again, getting a birthday gift, so thank you very much," Madison said to the artist.
(KUSA-TV © 2010 Multimedia Holdings Corporation)