KIEV, Ukraine — When Vasily Budik came out of his boss’s office at the Ukrainian defense ministry, the dark lines that etched his features betrayed the dark mood of much of the country. He’s a close adviser to the ministry, and he does not believe the ceasefire signed with pro-Russian forces in the east last week means permanent peace, or even an end to the fighting. But his main concern on Wednesday morning—the priority for the Ukraine defense minister—was arranging the release of more than 1,000 captives, both military and civilian, kept in jails and makeshift dungeons all over the rebel-controlled areas.

On Wednesday morning, the ministry’s officials got a call from Donetsk alerting them that one of their snipers had been captured and the separatists were threatening to shoot him in the basement of the old Donetsk police headquarters.

For Budik, that brought back chilling memories. He knows about those executions, some of them real, a few of them faked, only too well. He witnessed several of them during the three months, from mid-April to the end of July, when he was imprisoned in the breakaway east.

Budik had been arrested by rebel troops under the command of Igor Bezler, nicknamed “Bes,” or “The Demon,” in the town of Horlivka. The rebels suspected that Budik, a Georgian citizen, might be spying for a foreign intelligence service. Budik told them that he’d lived in Ukraine for over 20 years and had served his adopted country faithfully, but his tormentors either didn’t believe him or didn't care. During the drawn-out negotiations for Budik’s release, at one point he was lined up against the firing-squad wall. And that was not the worst of it.

So, while Budik is working hard to help win the freedom of those still detained in eastern Ukraine—about 700 prisoners and wounded soldiers had been freed by Wednesday, according to Ukrainian President Petro Poroshenko—Budik is hardly sanguine about any long-term agreement.

“Forget about this peace agreement,” Budik told The Daily Beast. “You will see, Russia will attack us in a week or two. When was the last time Russia kept promises?”

Budik’s Georgian experience is one source of his distrust: “I was in Abkhazia in 1993, when Georgia agreed to a ceasefire deal with Russian-backed Abkhaz forces, but the Abkhaz attacked us two weeks later together with Russian and Chechen military, the same way they are attacking us today in Ukraine.”

After Budik had been held for about a month by the separatists, his body was covered with wounds and infections were setting in. One day the pro-Russian rebels tortured him for over four hours, asking, “Who are you?” the whole time. Through most of that session he was lying on a bench, his hands and feet bound with tape. “There were eight interrogators around me demanding I tell them which intelligence service I worked for, NATO or the Mossad,” Budik said. “Two of them stuck knives into my hips and shins.”

But that was not the end of Budik’s suffering. On May 23, Denis Pushilin, one of the separatist commanders in the self-proclaimed Donetsk People’s Republic, decided he might be able to exchange Budik for an apparently very valuable woman in Ukrainian custody: Olga Kulygina is a 40-year-old pro-Kremlin political analyst working for ANNA-news. She is reported to be a close friend of Igor Strelkov, one of the key leaders of the Kremlin-backed push in what Russian President Vladimir Putin likes to call Novorossiya.

The interrogators wanted Budik to help them negotiate his own swap with Kiev. The rebels were willing to give first 10, then 14 prisoners in exchange for Kulygina, but Kiev was still asking for more prisoners. So Bes, “The Demon,” lost his famously short temper. On June 3, the rebel leader announced he would execute Budik and another captive, a secret police colonel. In the video posted on YouTube and elsewhere, the two Ukrainian officials are shown standing with their faces to the wall in the half-lit basement of the former police station, waiting for their execution. In the foreground a rebel in a camouflage uniform addresses the Ukrainian leadership: “The death of these men is your fault,” he says.

Budik did not know when he was taken there whether he would live or die. “Our executioners told us there would be one fake shot, and one real shot, so we were supposed to fall after the first one if we wanted to live.” But there was no way, as they stood there blindfolded in the darkened room, to know if they were being told the truth or not. Budik had witnessed other executions that were all too real. Were those victims also told one shot was meant to miss? When was the last time the Russians kept their promises? Then the shots rang out. Budik and the other man fell.

The video of the simulated execution was published on the Internet the same day, to the horror of the victims’ families.

Eventually, Kiev agreed to swap Kulygina for 17 captured officials, including Budik.

He says he believes it was good professional stamina that saved his life. His captor, Bes, respected unbreakable enemies, he says. But nothing was predictable. Budik says that in all he saw 11 genuine executions of Ukrainian prisoners during his imprisonment, and at least 21 more people were shot in other locations during June and July. Meanwhile, as if to keep the paperwork straight, the separatist government in Donetsk has formally introduced the death penalty.

So, Ukrainian military officers have good reason to feel skeptical about the ceasefire today. Their army that originally fielded 50,000 servicemen, most of them fighting in volunteer battalions, has lost over 1,000 soldiers—the number that military men consider a point of no return, a red line making it difficult to make any further concessions.

The rebels keep reminding Kiev that they would stop killing Ukrainian soldiers if Ukraine will give up forever its claims to the eastern regions. “Either they leave this land themselves, or we will discard them like kittens,” says Alexander Zakharchenko, the prime minister of the self-proclaimed Donetsk People's Republic. He was talking about the kinds of kittens that are drowned when nobody wants them.

As of this writing, the fate of the captured Ukrainian sniper remains unknown.