She goes on to explain that they'd been out for the evening and had no more than a glass of wine each alongside a meal at a favourite restaurant, one where they had eaten many times before. A minute or two from home, they stopped at a set of lights.
"A friend of ours stopped next to us at the lights, just by chance, and we chatted and waited for the red light to change to green. Then, he threw a piece of chocolate at us, just as a joke. It flew through the window, straight into Glenn's lap. He picked it up, popped it in his mouth, and then we drove off laughing."
The half mile home was uneventful, but as they walked through the front door, Glenn felt his throat starting to tighten.
Jana, worried that Glenn was choking, woke their housemates not knowing what else to do. One of them called for the ambulance, and five or so minutes later I arrived. Glenn is unable to speak, but the signs are classic enough. Textbook cases of anything are rare, but this one was just that. Anaphylaxis kills, and it kills quickly. Glenn's oxygen levels were low, his blood pressure dropping, and the unknown chocolate the final giveaway when Jana remembers he's allergic to nuts. He's carried an Epipen for years, but had never had to use it. The only one he had was ten years out of date.
As I prepare an injection of adrenaline, I place a mask on his face forcing oxygen laced with salbutamol into his lungs, hoping to prise open his airway. He's rapidly becoming less responsive, fighting to keep his eyes open, struggling to stay conscious. The injection into his upper arm is a last gasp attempt, but within seconds it's clear to see that it's working.
Two minutes later, the crew arrive, and as they walk in, Glenn greets them.
"Hey guys, I'm alright now!" His breathing is still a little laboured, and a loud, audible wheeze rasps across the room. It's a much better sound than the total silence of only minutes earlier.
"Don't you EVER do that to me again!" Jana slaps him on the shoulder, and then crumples sobbing into his arms.
Glenn's wheeled out to the ambulance, his oxygen levels vastly improved and his cheeks a flushed rosy colour. In the ambulance, his blood pressure is up, the wheeze is slowly being replaced by clear breaths, and he's almost able to complete a whole sentence without becoming breathless.
Most importantly, the look in Glenn's eyes has changed. Now he no longer thinks he's going to die - he knows he's going to live.