Obama's two days in Washington were mostly quiet, and concluded with the president receiving his daily national security briefing in the morning and joining Vice President Biden to huddle with members of his economic team in the afternoon.
Administration officials have insisted for weeks that the president just wanted to return to the White House for a series of meetings, but the explanation was met with a healthy dose of skepticism, because Obama rarely interrupts his vacations.
Judicial Watch estimates the extra trip cost $1.1 million. Only daughter Malia accompanied Obama back to Washington.
Speculation for why Obama returned focused around the possibility of a secret foreign leader meeting or the rollout of a new administration initiative on immigration or corporate taxes.
But no such explanation materialized.
The most unusual deviation from a normal day at the White House was Obama's dinner Monday night at Sam Kass's home. The president, joined by deputy chief of staff Anita Breckenridge, spent nearly five hours at the White House chef's Dupont Circle duplex apartment.
It's possible that the party may have been a celebration of Kass's impending nuptials to MSNBC host Alex Wagner. The couple announced their engagement last September. But the White House provided no details of the meal.
White House officials have bristled at repeated questions over the decision, even as the story has popcorned across the Internet.
"WH claimed Obama can do everything on the Vineyard, so why did he need to fly back to WH to meet with staff?" tweeted Joseph Curl, a Washington Times columnist and editor of the Drudge Report. "So wait, both Obama AND Holder flew from the Vineyard to DC so Holder could update Obama on Ferguson? Something very fishy going on here."
One possibility is that Democrats were simply wary of the president taking a full two-week vacation ahead of November's midterm elections. Obama's approval ratings are already sputtering in the low 40s, and Republicans have attacked his decision to retreat to the Vineyard.
Yet Obama and the White House have repeatedly signaled they worry little about such perceptions. Minutes after he gave his first public remarks last week about the racially charged protests in Ferguson, Mo., Obama was out on the golf course on Martha's Vineyard.
The Republican National Committee released a Web video last week criticizing the president's golf outings.
"Not too much comes between this president and his vacations, even these three major crises overseas. America needs a president who is more concerned with supporting our allies than working on his golf game," the RNC said in a statement.
Press secretary Josh Earnest insisted earlier this month that the return did not reflect sensitivity to the optics of the president's vacation.
"The president recognizes that he is president of the United States 24 hours a day, seven days a week, wherever he happens to be," Earnest said. "And the president will be in a position to fulfill the core functions of the commander-in-chief and ensure for the safety and security of the American people wherever he travels."
While fiscal-cliff negotiations in 2012 caused a Washington interruption to his Hawaii holiday, Obama did not return to D.C. last summer as Egypt's government tottered.
Nor did he fly back after the attempted underwear bombing of a Northwest flight headed to Detroit in 2009, or the Russian incursion into Ukraine during a golf weekend in Key Largo earlier this year.
Besides his meetings on Tuesday, Obama held separate meetings Monday with his national security team and Attorney General Eric Holder, and fielded questions from reporters at a brief news conference about Iraq and Ferguson.
But Obama didn't need to return to Washington to meet with anyone.
Holder traveled with the president to Massachusetts, and the White House posted pictures of Obama discussing the situation with the attorney general and Missouri Gov. Jay Nixon.
Obama can also teleconference in to a meeting with his economic or national security teams from Martha's Vineyard, something the White House has underlined.
"He travels with a wide array of communications equipment, and we also travel with a staff that allows us to have robust operational capabilities," White House spokesman Eric Schultz said last week.
If Obama wanted to speak to the media, he can do that on vacation too. The president made three public statements during his time on Martha's Vineyard last week.
Obama's lunch with Biden on Monday was symbolically important for the vice president after Obama partied with Hillary Clinton - Biden's likely rival for the 2016 Democratic presidential nomination - last week in Massachusetts. But that meal, which was closed to the media, hardly necessitated a return from Martha's Vineyard.
Something is in the wind, or Mr. Vacation would not be giving up precious Golf time.
What could it be?
Since he entertained no visitors, what business was conducted that caused him to return, minus Michelle?
Making secure phone calls to Foreign Embassies and Leaders would top my list.