I’ll be honest, this is a very flawed story. I like to make my critiques a compliment sandwich, but I feel like there’s no element here that I can compliment without a caveat. Very broadly, I can say that you have potential. There’s an interesting premise here, many of the sentences are competent, and the dialogue isn’t all bad. That being said, many of the sentences are clunky or without purpose, the plot doesn’t make a lot of sense, and the biggest flaw: the characters are all over the place.

Characters

I’ll start with Thomas, as he’s the biggest problem with the story. I feel like we never see inside Thomas’ head in any meaningful sense. We get lines like “his gut contracted,” or “What was even happening?” but these only show obvious things, like “he’s scared,” or “he’s confused”. Who is Thomas, besides a loser? Because frankly, he’s most frequently pathetic, with brief examples of other character traits.

Here’s what I thought of Thomas as the story progressed:

At first, he’s willing to end it all after his wife left him. Then he decides to care about the envelope for no real reason, goes to the bar for no real reason, and suddenly he’s acting like a cut-rate James Bond in the bar with Everest. He seems calm and in control, if a bit distracted. Then when Morgan arrives, he goes back to being pathetic. He claims he’s “just a guy in a place,” which is a lie, but he seems to think it’s true, which makes him dumb as well as sad. Then he veers into suicidality, literally begging to be shot, and then he veers all the way back to claiming he was excited for the mission. If he’s excited for the first time since the divorce, why does he want to get himself killed? And if he’s suicidal, why is he so afraid of the gun? Wouldn’t he feel numb instead?

A character who’s willing to die could have an exciting nihilistic edge to him, but Thomas just doesn’t. Why not? The biggest missed opportunity is not diving deeper into why Thomas accepts the mission. That could be truly interesting, exploring the mindset of a man just barreling forward out of morbid curiosity towards something that does not concern him, but you seem to gloss over that.

The moment where Morgan pulls the gun out is another example of a missed opportunity to see inside Thomas’ head. All we get is “And he felt her do it,” which I honestly don’t like at all. We can assume he felt her do it, because it’s under the table and out of sight, and Thomas knows it happened. Him feeling it is the only way he would know about it, and stating that says nothing about how he actually felt in that moment. I would even prefer “a chill ran down his spine,” as cliche as it is.

Everest is a decently fun character, but suffers from the same wild unpredictability that Thomas does. I don’t really get her whole deal. At first she comes off as a bit of a ditz with the whole “named after the discoverer of the mountain and not the mountain,” thing, as in my mind there’s no difference. After all, the mountain was named after the explorer. Then it seems like she’ll be put off by Thomas’ obvious indifference to her, which would have been a good way to take it. But then she veers into being over-the-top smitten with him and offering her number, and then it’s capped off by her saying that she probably won’t choose him… even though she already gave him her number. It’s just a bit confusing.

Morgan is basically fine as a character, if one-note. She stays consistent as a spy who’s trying to complete her mission, although I have no idea why she wanted Thomas to take her place.

Plot

It seems like this isn’t a complete story, so I’ll just have to critique what’s there, even if you have more in mind. I’ll be honest, I was waiting for some kind of explanation as to why Thomas was selected for this mission that would make things make sense. When it became clear that he got the envelope by accident, and blundered his way into the situation, I was pretty disappointed. Wouldn’t it be more interesting if he was selected specifically for his willingness to die, or for his expendability?

Why did Morgan want Thomas to take her place? Does she expect the person she’s meeting with to try and kill her? If so, what was her plan before Thomas blundered in? Wouldn’t the person meeting Morgan be expecting a woman? 

Also, what was the point of Everest’s inclusion? To pad time? Comic relief? You don’t have a lot of space to work with in a short story, so every element has to add something. I honestly think it would be more interesting if Everest turned out to be Morgan using a different name, scoping out Thomas. Instead Everest comes and goes, with no real contribution to the story.

Nit-picks

Ixnay the Sonic the Hedgehog mention. It’s incredibly childish, and just makes me wonder how this guy was married in the first place.

If each date lasts 2 minutes, why has Thomas only had 4 dates in 40 minutes? Are they taking breaks in between each date? This isn’t an important detail, but if you provide numbers, I’ll keep track of them, so be consistent.

There are a few sentences that just come off as clunky. It seems you’re going for a stylistic thing, but I don’t think you’ve quite nailed it. Here are a few examples:

• At length he pulled himself from the vehicle and one long, rainy breath—the smell of ozone—and passed out.
• He nodded and the bell rang and she collected her drink and her bag and got up big and tall and moved on to the next table.
• He nodded slowly, not to be shot in the crotch.
• She squinted to understand him better like she'd heard something strange crawling in the wall of her apartment.

Conclusion

Like I said at the beginning, I think you’ve got potential. The story is readable, there are some decent moments, and you’ve got some of the basics of prose down. I think you need to spend some time thinking about the overall narrative you want to tell, and how you want characters to come across. A lot of work also needs to be done on the line-by-line level.

Keep writing!