The Duke and Duchess of Cambridge have vowed to "do whatever they can – when the time is right" as the last Royals standing on the front line of the coronavirus battle.
The couple have been working "flat out" while other members of The Firm are nowhere to be seen.
As Prince Charles was diagnosed with the virus and the Queen and Prince Philip remain in isolation, the Sussexes have fled their Canadian enclave for a new life in Hollywood.
But while Meghan left Palace staff "aghast" with news of her Disney film voiceover, William and Kate have displayed an iron will, focusing on supporting British people and the NHS.
Royal sources told the Sunday Mirror: "In extraordinary times, you need an extraordinary effort.
"The Duke and Duchess have links to many sectors, the willingness to show unity with the country and an ability to bring people together.
"As other family members are out of action, they have been working flat out and stand ready on the front line to do whatever they can but when the time is right.
"William has spoken of his sense of duty and now, in the midst of this crisis, he feels it more than ever."
Palace insiders confirmed William and Kate will make further contributions after the lockdown is lifted.
They released an emotional video – viewed by five million – showing Prince George, six, Princess Charlotte, four, and Prince Louis, one, applauding NHS staff.CHARLOTTE, GEORGE AND LOUIS cheer on THE NHS
A senior Palace source said: "It was the family's way of saying, ‘We are behind you and we thank you for all you are doing to keep the country safe'."
William, 37, is patron of homeless charities The Passage and Centrepoint.
He told Mike Clarke, chief executive of The Passage: "We are in a life and death fight to help those living on the streets in this public health emergency."
His voice was heard in power and the Government has urged councils to give shelter to all rough sleepers by tonight.
Wills and Kate have been working tirelessly with government, emergency services and charities.
They visited NHS heroes at a 111 centre in Croydon, South London, two weeks ago.
Wills said he missed the front line, recalling his days as an air ambulance pilot.
He has even discussed "virtual visits" via video link to highlight causes if the virus prevents being there in person.
The Queen, 93, is isolating alongside Philip, 98, at Windsor and is being updated by courtiers and virus-hit PM Boris Johnson.
Talks with No 10 have taken place for the Queen to address the nation in the midst of the pandemic.
Charles, 71, is "working from home as usual" after being forced into self isolation when he also tested positive.
But with him and wife Camilla, 72, absent, the baton passes yet more firmly into the hands of William and Kate, 38.
The Royal Family has a history of standing steadfast with the public.
During The Blitz in World War Two, George VI and the Queen Mum visited London's East End.
Prince Harry, 35, meanwhile, was reported to be feeling "helpless" at the current situation as he and Meghan, 38, are on the other side of the Atlantic.
They posted Instagram messages saying they would try to "focus on inspiring stories" – adding: "We are all in this together and as a global community we can support each other – and build a digital neighbourhood that feels safe for every one of us."
But Palace staff are very uncomfortable with Meghan's relaunch of her Hollywood career and a move this week to Tinseltown – just days before she and Harry cease to be working royals.
One well-placed Palace insider said of her Disney deal: "There were more than a few raised eyebrows. Everyone was aghast, it just seems so off-message.
"Some have asked whether Harry and Meghan would come back to help out once the lockdown is over but that's definitely not going to happen."