Regretful night

one night I was hanging out with my best friend over at his friends house, we were talking laughing having a great time. I unexpectedly get a call from an older friend that I haven’t talked to in over 6 months at that point. It was around 1 am and I answer and had asked me to hangout. I haven’t seen them in a while so I agreed to go and see them. I was informed that they were with another mutual friend of ours (which part of the reason to agreeing), I drove about 45 minutes to them and once I had arrived I see it was only that one person. Confused but didn’t really question. (Red flag #1) as we sit and talk for a little while they had made a couple offered to me that I declined, not what you would think but definitely not appropriate to post on here. (Red flag #2) we had sat for a little bit longer and they offered to play a game as we all know as “Pokémon go”.. mind you at this point of time it’s about 3 am and I was skeptical but I knew them and they knew me, what’s the worst that could happen, right? (Red flag #3) I was shown the map of their normal route which was literally a square around the building. Didn’t seem to sketchy. We go outside and we head straight, then turn left, they take their shoes off in the middle of the street and left them there, and we just kept on walking. (RED FLAG #4!!!) we were supposed to turn back towards the building but had kept walking and eventually got to this empty soccer field. I’m not familiar with the city we were in so I didn’t know where we were at that point. We stop and just kind of stand there and they said they need to use the bathroom and was going to go in the bush. I said ok walked a bit away and they went the other. After a minute I flash my light since I wasn’t hearing them. I look around and they are no where to be found. I start calling out their name and I don’t see them anywhere. In a panic I try to find my way out of the field and from a distance I hear them screaming. I look all over and can’t see a damn thing. I start to freak out and my anxiety is at an all time high. I try to call my best friend over and over and over but no answer. I find my way out of the field but have NO IDEA how to get back. All my stuff was at this persons apartment and they are no where to be seen. I try to call them and my calls kept being rejected then my number was eventually blocked. As I’m wandering the street looking for familiar signs I keep hearing noises around me and I did NOT want to look back. About an hour later I find my way back and my friend eventually answered. But I still don’t have any of my belongings and no way to contact this person. I gave their number to my friend to text and they eventually answered and said my stuff was outside. Looking around I find the sweatshirt I was wearing on the ground on the sidewalk. But my backpack and bag are not there. I go to the side of the building and there I find my backpack. But my bag? The only other logical thinking I could know where it would be is behind the building. All dark and unseen from the public I chose to not go back there. All I could think in my head is “this person is crazy, what are their intentions, when would they do that” I go across the street to a Dunkin’ Donuts where it had just opened and I was around a crowd of people feeling safer than ever. I open my backpack and my bag was inside my backpack (thankfully). about an hour later almost 5 am my friend finally arrives to come rescue me from this crazy experience. Hyperventilating I hug them and get in the car. I tell them what hapoened and I never spoke or saw this person again.