Doctor Lago was with her kids, Doctor Fernandez was at Pilates class and Doctors Arsuaga and De la Calle were eating chocolate ice cream, when the call came about Ebola.
They were taking some down-time after several tough weeks trying in vain to save the lives of two missionaries who caught the disease in Africa — but now it had struck one of their own colleagues.
The infection of a nurse in a hospital in Madrid put the four doctors and their team of about 50 staff in the front line of a worldwide battle against a still uncurable disease.
"We are pioneers," said Fernando de la Calle, 33. "Ebola is very aggressive. It explodes and in a few days it destroys you. Like a tsunami, it devastates everything in its path."
On October 6, nurse Teresa Romero, 44, became the first person known to have become infected with the haemorrhagic fever outside Africa, where it has killed nearly 4,500 people.
For these doctors who treated the missionaries along with Romero and scores of other staff at the Carlos III hospital, that meant a further step into uncharted territory.
"There has been hardly any research published on Ebola. All that is known about it is contained in about 15 papers," said Mar Lago, 45. "It is ugly and very clever and it defends itself."
Lago received the news of Romero's infection in a text message on her mobile phone.
Marta Arsuaga received it as she was eating chocolate and lemon ice cream at the start of a holiday in Palermo with her colleague and friend De la Calle, 33.
"I said to myself, 'It's not possible'," recalled Arsuaga, 32.
They rushed back to a Madrid gripped by anxiety over Ebola and fears the virus was spreading across Europe.
"It was crazy. The telephones wouldn't stop ringing. Messages were flying in from all over: family, friends, journalists," said Belen Fernandez, a 47-year-old biologist.
The doctors hunkered down in Carlos III, working in shifts to save their colleague.
Lago has been working right round the clock three times a week and hardly seeing her teenage son.
"There have been several critical moments. I was on duty one of those nights. Teresa nearly passed away," she said.
The doctors wear thick, clumsy protective suits to shield them from any bodily fluids that could infect them with the disease.
The suits are difficult to put on and take off and, while wearing one, a doctor's bedside manner is muted by a face mask.
"You can touch patients but you can't examine them internally," Arsuaga explained.
The doctors avoid going into Romero's room as much as possible, talking to her via an intercom and monitoring her body language on a video screen, in awe of the brutal virus.
Belen prays before starting work, she said, showing a silver pendant with an image of the Virgin Mary.
Fernando said he wasn't generally religious but now he is carrying in the pocket of his white clinical trousers a rosary he inherited from his grandmother.
Besides fighting for the life of a colleague, the doctors also want to save Teresa so that the experimental treatments they are trying may later be used on patients in Africa in the hope of developing a cure — a professional challenge.
"I like working on acute diseases," said Lago.
When the first of the two Spanish missionaries was brought back from Liberia with Ebola in August, the team did not know where to turn for information, said De la Calle.
But now they have weekly conference calls with hospitals abroad, organised by the World Health Organisation.
After several tense days, Romero's condition improved this week.
She has been talking and asking for music and photographs of her loved ones, the doctors said on Thursday, feeling a tinge of hope.
But hours later, their race against the virus speeded up again, when three new patients were admitted to the hospital to be tested for Ebola — tests that have since come back negative.