Sabah Abd El-Fatah, 47, speaks about her son, Mohamed Sadiq, 25, who is among Egyptians who disappeared during Egypt's 2011 revolution. (Ernesto Londono/WASHINGTON POST)

Mohamed Sadiq’s last words before walking down the staircase of his family’s modest apartment building on Jan. 25, 2011, gave his mother chills.

“I am not coming back until Mubarak is gone,” she recalls the 25-year-old saying as he set out to join the growing protest movement that 18 days later spelled the end of President Hosni Mubarak’s autocratic reign.

Eighteen months later, the fate of Sadiq and scores of others who demonstrated and battled riot police during those dramatic days remains a mystery. Relatives have searched morgues, hospital logs and prisons in a desperate quest for clues. Some of their findings suggest that security officials carried out abuse and unlawful detentions as the embattled regime sought to thwart the revolt, activists say.

“There are people missing who were not at the morgue, not in hospitals and not in prisons,” said Nermeen Yousri, an activist who earlier this year launched a campaign called We Will Find Them. “They didn’t evaporate, so there has to be something.”

Advocates for families say they have been tracking about 60 cases, a figure they believe represents a tiny fraction of the total number of people who vanished during the height of the revolt and the period of military rule that followed.

“I think we’ve just scratched the surface,” said Hossam Bahgat, a prominent human rights activist.

A son committed to the cause

Sadiq’s mother began her quest a couple of days after he left home. He was a good son who studied hard, earned a degree in international trade and learned English. Having had no luck finding work in his field, he took menial jobs. It made him bitter about living in a country where getting ahead was next to impossible, she said. He linked up with like-minded Egyptians on the Internet and was thrilled to be on the front lines of the revolt.

“He saw the revolution as an opportunity because he felt the country was ruined,” Sabah Abd el-Fatah said, recalling her son’s disdain for Mubarak and for his son and heir apparent, Gamal. “He would say: ‘We don’t want Gamal to rule us. We don’t want this kingdom to continue.’ ”

As Egyptians battled security forces in the days that followed, Fatah, 47, said she began going to morgues and prisons every day, shoving her way through throngs of people who were also looking for loved ones. She held her breath in anticipation as she raised sheets from dozens of corpses, then ruled out one cadaver after another. And she dialed her son’s cellphone obsessively.

On Feb. 11, the day the country’s generals forced Mubarak out of power, Fatah’s nephew got a text message from Sadiq, asking him to call his phone, which was out of credit.

When Fatah got through, she said, she heard her son whispering. She was able to make out that he was in the custody of state security officials and was among a group of prisoners being moved. The call dropped. The next time she got through, she said, a police officer answered. The man told her he could not help her and hung up.

Weeks later, she got through to a man who said he got the phone from his brother, a soldier. Fatah spent the months of military rule running from prison to prison, traveling across the country. She always got the same answer: He’s not here; we can’t help you.

Some of the parents she met who were also searching for missing children have given up hope. Some have even held funerals without bodies, seeking closure.

A father’s fruitless hunt

Across town, in a crowded neighborhood near the famous Giza pyramids, Said Mahmoud, 54, worries that he’ll never see his son and daughter again.

Amr Said Mahmoud, 18, vanished Jan. 28, the revolution’s “day of rage,” during which Egyptians burned Mubarak’s National Democratic Party’s headquarters and other state facilities across the country.

After his son disappeared, Mahmoud’s father became a die-hard revolutionary. He went to Cairo’s Tahrir Square to plea for more to be done to find the missing.

“I got up on a stage in Tahrir and said that if the missing-persons’ file was not addressed, I would hang myself in Tahrir,” he recalled recently.

His son was released July 17, 2011, from a prison in northern Egypt, filthy, ragged and traumatized. He found his way home. The family was offered no apology or explanation.

The young man wandered aimlessly around their home for a few days looking dazed and angry. When his father pressed him for information about his time in captivity, the boy broke down.

“I was raped,” the man remembered his son saying. Shortly after making that revelation, Amr Said said he was leaving home. “I am going to go fight and to avenge this with my own hands,” he said. It was the last his family heard of him.

Enraged, the senior Mahmoud resumed his visits to Tahrir to protest the military’s initial refusal to give up power. He often took his 17-year-old daughter Samah, who has a learning disability. He would typically send her home on the metro after sunset and spend the evening protesting alone.

On Feb. 2, she boarded the metro but never made it home. The family thinks her disappearance may have been related to her brother’s run-in with authorities, or to her father’s complaints. The possible scenarios haunt Said Mahmoud. Had pro-regime thugs he often scuffled with in Tahrir kidnapped his daughter? Had she been assaulted?

Said Mahmoud said he has searched every hospital, morgue and police station in this metropolis seeking clues. He has found none. The police officers and prosecutors who agreed to help him often look ashamed, he said, and some have quietly confided that they are under orders not to discuss cases of missing people.

Disappearances were relatively rare during the Mubarak era, and most such cases involved Islamists who Bahgat, the human rights activist, said were presumed to have been killed while being tortured.

Having no more hospitals or morgues to visit in search of his children, Said Mahmoud has settled on a near-daily routine that ends late at night, always in disappointment.

“Now I just walk down the street,” he said. “I take the bus from one end of the city to the other and keep looking at people out the window. Other days I take the metro for hours, looking.”

Ingy Hassieb contributed to this report.