When I met Hazem in June, he had no understanding of how the turmoil in Syria could have claimed his brother, whom he insisted was not political.
Neither was Hazem, a medical researcher and adjunct professor at Thomas Jefferson University.
He is now.
Next to his coffee were notes for a speech he planned to give on Saturday at a vigil for 300 children killed during the protests against the regime of President Bashar Assad.
"I end up in this thing, and I'm not prepared," said Hazem - wiry, soft-spoken, and dressed in black. "I'm a scientist, but I got thrown into this."
Since June, he has stopped working and has dedicated himself to finding answers to the mystery of his brother's last days.
A Syrian politician who was friendly with the family said Sakher had been grabbed by the mukhabarat, the state intelligence agency, as he left work one night.
A spokeswoman for the Syrian Embassy, Roua Sharbaji, denied over the summer that authorities had detained Sakher. His death was criminal, she said, not political, and the matter was under investigation.
I asked for an update last week. But this time the spokeswoman didn't reply.
The United Nations Human Rights Council estimates that more than 4,000 people have been killed in Syria since the uprising began in March, and as many as 40,000 have been detained. Council investigators found "patterns of summary execution, arbitrary arrest, enforced disappearance, torture, including sexual violence . . . ."
Amnesty International wrote in an August report that Sakher "may have been a target for Syrian security agencies because of a three-week visit he had just made to the U.S.A., which may have raised suspicions that he wished to support the protest movement by liaising with Syrian opponents there."
Two other doctors, the human rights group reported, said security forces had threatened them, telling them they could wind up like Sakher.
That's why his brother was grabbed, Hazem said. He was prominent. Hazem figures Sakher's biggest sin was signing a petition to change the Syrian law requiring physicians to call authorities before treating anyone injured in a political protest.
"He was taken as an example," Hazem said.
Over the summer, Hazem received a call from someone using an untraceable satellite phone who offered to sell him photos of his brother's body. Hazem paid $300 for them.
"You could see the terror etched on his face," he said.
As he reached for words to describe the body's condition - "like something in a butcher shop" - and how that made him feel, the woman sitting next to us left the cafe. The conversation was too graphic for her.
"Too bad," Hazem said, and he sat for a moment alone with his thoughts.
The death of his brother has challenged his faith, he said. His wife and teenage son and daughter worry about him, he said. They wonder when he will come home and be as he used to be. He wonders himself.
"My closure will be when Assad leaves," he said. "Then I will be able to go back to my family and my work. Then I'll go back to my normal life."
Contact columnist Daniel Rubin at 215-854-5917, firstname.lastname@example.org, or @danielrubin on Twitter. Read his blog at philly.com/blinq.