Barnes & Noble (BKS) on Tuesday ousted its Chief Executive Officer Ron Boire less than one year into his tenure, saying he “was not a good fit” in an unusual rebuke for such a corporate announcement. The move plunges the No. 1 U.S. bookstore into new turmoil just as it tries to execute a new turnaround plan.

Boire, who took the reins of the struggling bookstore chain only last September, had previously been CEO of Sears Canada, also a struggling chain and before that, chief merchant at Sears Holdings (SHLD), a retailer dealing with dramatic sales declines. Earlier this decade, Boire was CEO of Brookstone, a retailer that filed for Chapter 11 bankruptcy after he left.

The sudden departure of Boire creates new challenges for Barnes & Noble at a time it is trying to renew itself. In a turnaround plan Boire unveiled to Wall Street analysts barely two months ago, Barnes & Noble announced initiatives such as opening four concept stores in fiscal 2017 that will feature bars offering wine and beer, along with better food, in cafés twice the size of its usual food spots, among other efforts to rejuvenate its business.

While Barnes & Noble’s business has stabilized as the growth of e-books has slowed, the retailer has pulled back on its Nook e-reader business and last year spun off its college bookstore division, putting fresh pressure on the company to prove it can make its core bookselling business grow again. In the fourth quarter of fiscal 2016 ended in April, Barnes & Noble’s comparable-store sales fell 0.8% and the company expects those figures to rise only modestly in the current fiscal year.

When dismissing a top executive, most companies use bland language and outline the departing executives achievements. But in rare language, the company was more direct if vague about the reasons for the departure.

“The Board of Directors determined that Mr. Boire was not a good fit for the organization and that it was in the best interests of all parties for him to leave the Company,” Barnes & Noble said in a press release.

Other C-suite executives will take over his responsibilities while Barnes & Noble conducts. Meanwhile, Executive Chairman, Leonard Riggio, the retailer’s founder postponed his retirement, initially set to take place on September 14.