Last Friday the Reader said hello to the Chicago Newspaper Guild, which this paper’s editorial employees certified by a vote of 19-0. On Monday the Reader began saying good-bye to editor Mara Shalhoup.

“I have accepted an offer to become the next editor of the LA Weekly,” she said in a note to her staff. “My last day at the Reader will be Friday, February 13—which might be creepy except that, statistically speaking, the 13th of the month is more likely to fall on a Friday than any other day of the week.” (This reference demonstrated Shalhoup’s mastery of Reader lore, as it linked to a story we’d published when she was three years old, one of many about which it could be said not another paper on earth would print this thing.)

Her note went on, “I recognize that the timing of this announcement is coming on the heels of your decision to unionize. I had accepted this job prior to last week’s vote but didn’t want to tell you sooner—because I didn’t want my decision to persuade you one way or the other.”

She tells me that after hearing that editor Sarah Fenske intended to leave the Weekly, she inquired about the job before she had any idea her Reader staff was attempting to organize. That was something Shalhoup advised against in editorial meetings, but not vehemently, and no bridges were burned. “I did not feel challenged working with a union going forward,” she says—and in fact, if that’s a dire fate, it’s not one she’s avoided: her future staff in LA is represented by the International Association of Machinists and Aerospace Workers.

“There’s a time in life—and if you live in Chicago, that time is January—when the possibility of a new adventure becomes irresistible,” she told her staff. “I love this city. I love working with all of you. I love the Reader. I also love exploring places I never imagined I’d be able to go. That’s the reason I came here four years ago. And it’s the reason I’m leaving now.”

“I like an adventure,” she says.

After decades of ample but unadventurous prosperity, the Reader was mired in upheaval when Shalhoup, who’s 38, arrived in March 2011. In 2007 this paper had been sold by its founders to the Creative Loafing chain in Atlanta. Fourteen months later the chain declared bankruptcy, and 11 months after that its primary creditor, Atalaya Capital Management, took it over.

Before long, acting publisher Alison Draper dumbfounded the staff by firing the Reader‘s longtime editor, Alison True; and when True’s successor, former managing editor Kiki Yablon, gave the job a few months and then decided to leave journalism, the paper was leaderless. Shalhoup understood what the Reader had been through with Creative Loafing from having edited that chain’s Atlanta paper; she applied for the Reader position. Just about everyone on the staff met her individually, they liked her, and she got the job.

In Chicago, she’s run this paper while Atalaya was in charge and for the nearly three years following its sale to Wrapports LLC, the group of investors who took over the Sun-Times and who moved the Reader from its longtime home at 11 E. Illinois into extra space in the Wrapports suite in the Apparel Center. This brief survey of the paper’s chaotic history since 2007 suggests what Shalhoup’s had to deal with, but it says more about why the staff finally voted unanimously to join a union.

Sun-Times editor and publisher Jim Kirk commented today, “We thank Mara for her many accomplishments during her four years as the editor of the Reader. Among her many successes, she led the Reader through a digital redesign that resulted in tremendous audience growth across our digital platforms. Her commitment to the editorial integrity and heritage of the Reader was evident throughout her tenure and helped the Reader win numerous prestigious awards from various organizations. We wish her nothing but the best as she goes on to lead LA Weekly. They are lucky to have her.”

It isn’t serenity that draws Shalhoup west. The history of the Weekly is every bit as tumultuous as the Reader‘s. The Weekly was launched in 1978 by refugees from the defunct Austin Sun and was sold in 1994 to the owners of the Village Voice. The New Times altweekly chain later found itself embroiled with Village Voice Media in a federal antitrust investigation involving their competing LA papers. In 2005 the two companies merged and became Village Voice Media, retaining the more luminous name; two years ago executives of the chain bought its papers and websites and named the new company Voice Media Group. They did not, however, purchase Village Voice Media’s notorious, which, the New York Times‘s Nicholas Kristof wrote in 2012, appears to be “the biggest forum for sex trafficking of under-age girls in the United States.”

As for the Reader now, who knows? Kirk says the search for a successor to Shalhoup will start immediately and both internal and external candidates will be considered. Next in line at the Reader is managing editor Jake Malooley. He’s been with the paper less than a year, though he’d earlier worked for Time Out Chicago since 2006 and knows the city.

One immediate concern of mine is that Wrapports, believing the Reader to be a little less special than its staff does, would appoint someone now at the Sun-Times to take over and bring the Reader a little more snugly into the fold. After all, if everyone in the office works for the same union, why maintain inconvenient distinctions?

But Shalhoup, who’s talked with Kirk about that possibility, says she’s certain it will never happen.

Correction: This post has been amended to correctly reflect the details of the sale in the 90s of the LA Weekly and the merger, more recently, of the New Times and Village Voice Media chains.