A prison nurse said her husband died in a fire. Then police discovered her relationship with murderer.

The fire scorched through the home on a dead-end street in the early morning hours of Dec. 11, 2018, in Iberia, Missouri, a tiny town of several hundred tucked in the Ozarks. It was about 2 a.m. when the neighbors called 911, and when firefighters arrived they found Amy Murray and her son and dogs safe, but discovered Joshua Murray's body lying motionless and charred on his bed.

Luckily for her and her 11-year-old son, Amy Murray told investigators, they had just slipped out of the house to run to McDonald's. They came back to find their home in flames, too late to save her husband, she said. The construction worker, a lifelong Missourian, was just 37.

In the days that followed, condolences poured in for Murray and her son from all across Missouri. But one man close to Murray didn't appear particularly upset, police say: Eugene Claypool, who, an hour up the highway, was looking forward to a new life.

Claypool, 39, had fallen in love with Murray, with whom he had been having an affair "for some time," the Miller County Sheriff's Office now says. The two met at the Jefferson City Correctional Center, a prison on No More Victims Road just south of the Missouri River. She was a prison nurse there, a 40-year-old with a college education. Claypool was an inmate, doing 25 to life for second-degree murder.

Murray had told Claypool in a recorded prison phone call that she wanted a divorce. But soon enough, Joshua Murray was dead - and to police it all seemed just a little too convenient. In another call after her husband died, police say, Amy Murray told Claypool what his death could mean for them: marriage.

That seems less likely, however, now that Murray is charged with first-degree murder in her husband's death, facing a life sentence of her own. Investigations by the fire marshal, police and the coroner revealed that a fire didn't kill Joshua Murray. Antifreeze did.

According to a Feb. 8 probable cause statement by the Miller County Sheriff's Office, arson investigators found that the fire was intentionally set to the bed in the master bedroom, leading investigators to believe that Murray set her husband on fire after he was already dead in effort to cover up the crime. The coroner found that he died of ethylene glycol poisoning, a compound used as an antifreeze. And police found a host of evidence that dismantled Murray's late-night McDonald's alibi, all of which led to her arrest last Friday.

Murray was scheduled to be arraigned on the charges Wednesday but was instead released on a $750,000 surety bond with the hearing rescheduled for next month, according to Miller County court records. Murray's attorney could not immediately be reached for comment late Wednesday.

Before investigators discovered the phone calls with Claypool, a half-eaten McDonald's sandwich was the first piece of evidence to cast doubt on Murray's story.

She told investigators that when she returned from her late-night McDonald's run to discover her home was on fire, the smoke was too thick to go inside to try to save her husband. But then why, investigators questioned, was there McDonald's food sitting on the kitchen counter?

Surveillance footage at the McDonald's in Osage Beach, Missouri, revealed that Murray, her son and two dogs did indeed go on a late-night fast-food run - but much earlier, at 11:48 p.m. on Dec. 10, according to the probable cause affidavit. The timing didn't make sense, investigators noted: Cellphone records indicated that Murray was inside the house 30 minutes before neighbors called 911 to report the fire, pinning her inside at about 1:30 a.m.

But in the days after Joshua's death, no one appeared to suspect anything other than a tragic accident.

His online obituary, picturing a bearded Joshua wearing pink suspenders and a bow tie, said he and Amy had been married since 2003. Mourners were urged to give money to the Josh Murray Memorial Fund. Family, friends, co-workers and neighbors spilled heartfelt words of support for Amy Murray and her son.

Meanwhile, investigators were just beginning to discover Murray's calls with Claypool - the evidence presented as a motive in the probable cause affidavit.

Murray and Claypool seemed to be confronted with two problems: Murray's marriage and Claypool's incarceration. He was up for parole in several years, but there was no guarantee he'd be released - possibly not ever.

His crime was not random, prosecutors said during his trial. On Christmas Day 2000, Claypool, then 21, broke into a house through a window with a 17-year-old friend, looking for cash, the Springfield News-Leader reported at the time. The man who lived there, 72-year-old Donald Harwick, had won a 1998 Missouri Lottery jackpot, a $1.7 million prize, and Claypool was looking for what remained of it. He and his friend thought they could get away with $10,000. Instead, they took $36 and Harwick's life, leaving a Bible on his chest after fatally stabbing him.

Harwick's family later made clear Claypool's crime would torment them "forever," as his granddaughter said in 2002, according to the Springfield News-Leader.

In the recorded phone calls reviewed by police, Murray talked about getting a lawyer for Claypool to try to fight for his early release. They seemed to be growing impatient: She told Claypool that she was tired of being around her husband and wanted a divorce. She said while he was on a trip to Nebraska that she hoped he never came home.

They changed their tune after Joshua Murray's death: They could finally "have a life," they said, now that Murray's husband was "out of the picture," according to the affidavit.

Murray told him she would start looking for an attorney.