The director of the Warsaw zoo and his wife always carried cyanide during World War II. Danger was ever-present but they were ready to take their secret to the grave.
The couple hid nearly 300 Jews and resistance fighters on zoo grounds during most of the war, under the noses of the German Nazis occupying Poland.
It sounds like a Hollywood movie, and now it is. But "The Zookeeper's Wife", which opens in Polish cinemas this week before rolling out internationally, is based on actual events.
Inside the zookeeper's villa, whose windowless cellar had a secret tunnel leading to the garden, Jan Zabinski and his wife Antonina gave refuge to the mostly Jews smuggled out of the city's ghetto.
"I remember squatting under this concrete shelf in the basement and keeping my hand over my sister's mouth to muffle her cries because she was constantly crying, day and night," said Moshe Tirosh, aged five at the time.
"When someone slammed the door upstairs, fear would pass through me, lest they find us," the 80-year-old told AFP in a telephone interview.
The retired businessman and grandfather-of-seven, who has lived in Israel since 1957, still cannot believe what he lived through.
"I saw children's dead bodies on the street. Terrible things... I remember wondering why everyone wants to kill us. I couldn't understand it," he said.
All but two of the zoo's hidden guests survived the war and Nazi troops stationed on the bombed-out zoo grounds never unearthed the subterfuge.
"My parents figured that it's always darkest under a lamppost," the zoo couple's daughter Teresa Zabinska said, citing a Polish saying according to which it is best to hide in plain sight.
"My father knew that it wouldn't occur to the Germans that so many people could be hiding in a place like this with open windows and no curtains," the 73-year-old told AFP.
Most hid in empty animal enclosures or the villa's basement. Others were able to stay with the family upstairs by taking on fake identities as Antonina's tailor or their son Ryszard's tutor.
Between 1940 and 1944, nearly 300 people found refuge, some for just a few hours or days, but others remained months or even years.
"Around 30 people would stay here at once," said Olga Zbonikowska, 38, who works for the Panda Foundation that takes care of the villa now.
The stakes were high. In occupied Poland, even offering Jews a glass of water was punishable by death.
Whenever a Nazi soldier got too close for comfort, Antonina would warn everyone by playing an operetta on the piano.
The hidden guests would escape through the tunnel or hide in a wardrobe upstairs that opened on both sides like a magician's trunk.
The couple also hid the Jews from their housekeeper out of fear she could give them away.
"The hardest was explaining away the increase in daily meals" to the housekeeper, Antonina wrote in her 1968 memoirs, saying the family fed the extra mouths by faking ravenous appetites.
"I can't believe how much they eat! I've never seen anything like it!" she recalled the housekeeper muttering.
Tirosh had suffered two years in the ghetto, marked by hunger, typhus and near deportation to the Treblinka death camp.
To escape Warsaw's Jewish quarter, his family paid off the guards and Tirosh and his sister were thrown over the wall in sacks while their parents climbed over.
On arriving at the zoo, Antonina's empathy and reassuring calm told them they were in good hands.
"She was extraordinary. I was a small boy who was very afraid of everything. But when I saw her face, I calmed right down. I still remember that feeling," Tirosh said.
Before the family moved on, Antonina tried to make them "look less Jewish" by bleaching their hair lighter.
"She locked herself in the bathroom with us and dyed our hair. She rubbed and rubbed and when we came out of the bathroom, Rysiek (nickname for the Zabinskis' son) cried out, 'Mum! What did you do? That's squirrel colour,'" Tirosh said, of the inadvertent reddish colour.
The family became known as The Squirrels. Others also had animal nicknames, including The Starling, The Hamsters and The Pheasants.
"Theirs was a house where both animals and people always found help," said Teresa, who was born at the zoo and had a raccoon-like coati from Mexico as a childhood playmate.
Aptly, her mother's memoirs -- to be republished this month -- were entitled "People and Animals".
They describe how Antonina pushed to raise funds to reopen the zoo after the war while Jan was in a Nazi German prisoner-of-war camp, having fought in the 1944 Warsaw Uprising.
American author Diane Ackerman relied heavily on the memoirs when writing her own 2007 nonfiction book "The Zookeeper's Wife", which inspired the movie. Directed by Niki Caro, it stars Golden Globe winner Jessica Chastain.
The Zabinskis died in the early 1970s.
The villa is now a museum where visitors can make an appointment to see the life-saving secret tunnel and basement.
Israel's Yad Vashem Holocaust remembrance center later recognised the Zabinskis as Righteous Among the Nations, a title bestowed upon non-Jews who helped Jews during the Holocaust.
"They believed it was the right thing to do," Teresa said, of her parents' wartime actions.
"My father always said that's what a decent person should do."