Last week, we reported exclusively that recently appointed Newsweek.com editorial director Will Tacy had left the publication. Yesterday, Newsweek editor Jon Meacham announced Tacy's replacement: senior editor Devin Gordon.

Gordon had helped reimagine the magazine's "Scope" section for its relaunch a few weeks ago and led Newsweek's front of book coverage, and his important position will not remain empty for long. National affairs editor Bret Begun has already agreed to step into Gordon's shoes, Meachum said. Begun has plenty of FOB experience, previously serving as deputy editor of the magazine's "Periscope" section, according to his Newsweek.com bio.

(Meacham's full memo, including glowing descriptions of Gordon and Begun's work, after the jump)

In other Newsweek news, the publication is desperately trying to publicize the disappearance of foreign correspondent Maziar Bahari in Tehran. According to the magazine, Bahari (right) was "detained without charge by Iranian authorities" on Sunday and hasn't been heard from since. A Newsweek spokesperson said this morning that there is still no update on his whereabouts.

Bahari, a Canadian citizen, has been living and working in Iran for the past decade, Newsweek said, adding that the pub "strongly condemns this unwarranted detention, and calls upon the Iranian government to release him immediately."

Our thoughts and prayers go to Bahari and his family, and best wishes to Gordon and Begun, taking on new challenges amid a dangerous time for journalists.

From Jon Meacham:

"I am delighted to announce that Devin Gordon will become the editor of Newsweek.com effective immediately. For years Devin has consistently proven himself to be a creative and energetic force for the magazine, and his reinvention of Scope for the relaunch is a terrific success story. In it he translated our core values in new and engaging ways, and I am certain he will help us do the same in the digital world. Working with Geoff Reiss and the Newsweek.com team, Devin will play a crucial role in both the day-to-day and long-term aspects of our evolving online strategy. This is great news for Devin, and for Newsweek.

After directing our coverage of a historic presidential race, Bret Begun has agreed to shift his formidable talents to Scope and the Front of the Book, and will become Scope Editor. Imaginative and scrupulous, Bret has excelled at every assignment he has undertaken for us, and Danny and Mark and I are very pleased that he will be the controlling authority on such a critical part of the magazine."