The coronavirus thrust sedate US Vice President Mike Pence to the forefront early this year when he was made leader of the White House pandemic task force.
Now it's pushed him out front again, after President Donald Trump was hit by the virus and forced into quarantine.
While Trump's symptoms reportedly remain mild, it has opened the possibility that the White House's behind-the-scenes man could not only be asked to assume the duties of president, but also take the lead in a presidential election race that has been almost entirely about Trump.
It would be a profound pivot for someone forced into the background for the three years and eight months of Trump's brash and calamitous presidency.
Pence -- who with his wife both tested negative for Covid-19 on Friday -- has been crucial to the Trump administration, a pillar of stability in a White House that has churned through top officials, and a magnet for a part of the Republican base dubious of the fickle real estate tycoon.
A lawyer by training and former radio talk show host who served in Congress for 12 years, Pence was governor of Indiana in 2016 when Trump recruited him as his vice presidential candidate.
The white-haired 61-year-old brought credibility as a traditional evangelical Christian who could appeal to church-going Americans and farm-belt conservatives who looked askance at the brash New Yorker.
The yin to the president's yang: where Trump is loud and offensive, Pence is taciturn and mannerly; where Trump flouts morality, Pence is deeply pious.
Where Trump's life has featured three wives and many more girlfriends, Pence is famous for saying he would not dine alone with any woman who is not his wife.
Ceding the stage
After taking office, Pence let Trump hold the entire stage.
He toiled quietly on important jobs like liaising with Congress and Republicans, and undertaking significant diplomatic missions.
And he smoothly adapted his earlier political stances to Trump's china shop-smashing approach to trade, diplomatic relations and immigration.
In early trips to Europe and Asia, he set the stage for Trump's resets of policy, while reassuring allies worried about Trump's ballistic rhetoric.
He also took the lead in Washington's aggressive policy to force out Venezuelan leader Nicolas Maduro -- while not accruing blame when that failed to achieve its goal.
And he stayed a team player, never betraying differences with Trump or promoting himself -- sins that cut short the careers of others in Trump's Cabinet.
In interviews and speeches he faithfully credits Trump's policies and actions and firmly defends the president against accusations of wrongdoing.
"I bring you greetings from the president of the United States of America," he declares in speeches, stressing he is only there because Trump asked him to be.
That didn't change in March when he was named as the public face of the White House coronavirus task force.
Echoing Pence's own personality, the scientist-heavy group's daily briefings sought to introduce calm, clarity and rigor to public information -- but only until Trump hijacked them and undermined their messages about social distancing, face masks and treatments.
While his staffers were some of the first to test positive for the disease, Pence continued to credit Trump's leadership.
His motive has never been clear. Has Pence been, like many vice presidents, biding his time for his own shot at the presidency?
Or does he tolerate Trump, like many Republicans, because in his position he can advance the social conservatives' agenda?
Earlier this year there was speculation that Trump, facing an uphill fight for reelection, would replace Pence with someone who might excite more voters, like former UN ambassador Nikki Haley or Secretary of State Mike Pompeo.
In the end the odd couple stuck together, and Pence has energetically promoted Trump on the campaign trail.
He spoke out Trump's name 33 times, with little reference to himself, in his address to the Republican National Convention in August.
"With President Donald Trump in the White House for four more years, and with God's help, we will make America great again, again," he said.