with his pregnant girlfriend ?

that's the one

They could not radio out for help during the shootout or use phones because the criminal was using a jammer . They found out they had to get to the basement to
cut the main power to stop the jammer .
But criminals were shooting in the halls so from an old ladiy’s apt somthey went in through the walls and down to the main power switch in the basement

Also the baby was born and the criminal made it clear he wasn’t leaving with out the baby and kept shooting and trying to get in where his girlfriend and baby were at.

His gang roamed the halls so the police cut through the walls to get down to the basement only way. Once the power was cut parts of the team radioed for back up and alerted the station but they were fending off gunfire in the basement . Everyone in the station was called out to help the big shoot out at the apartment complex
and the captain told the rookie at the station “get moving you are going there with me too.” The rookie is back in action as the group of squads move to the apt complex

The captains son was the one who cut the power and was still holding off gunfire in the basement with his partner . Meanwhile upstairs in the apartment where Chen and partner had delivered the baby (the baby was born) the criminals figured to go through the walls to get in to that room and came through the walls using a saw to get the baby and girlfriend just as backup from the station arrives .
The first 2 cops entering the complex are shot as soon as the elevator door opens but are helped from an apt by Bishop to get cover and she is able to help one officer live, but the other dies quickly
Finally, as more backup comes, the criminals are subdued and the captain sees the rookie help cuff the criminals who had been shooting at his son.
His son and all other main characters survive the shootout
As the criminal is taken away in a car he is told by the one officer’s wired ex wife he shot is still alive and the officer vows his wife will live and will put him away for life . He visits his ex wife at the hospital and looks like she will live and maybe get off drugs

Meanwhile back at the station in the captain’s office he tells the rookie his second investigation case is closed , he is back on active duty because the captain saw today that his action at the shootout means he is ready to go back on duty when he helped and besides , the home attacker who tried to kill the rookie has been giving false information , so of course the rookie is glad the lie he told about being home alone is never found out by the investigation and he is told to go home and relax because tomorrow he is back on duty

That night Chen visits him at home they are both wiped out / shook up from the shoot out and also the tension of the lie to the force
She asks how he is and tells him “ I delivered a baby today” talks about the shoot out but also adds at the end of the topic that sometimes she just wants to talk to him more like a friend .
They have a beer out on the balcony and he suggests maybe a pizza
she tells him she has already ordered pizza and it should be there soon and it ends with him reaching for his own beer as they talk looking out at LA
I think that’s how it ends . I was multitasking
Good luck following anything I have here hope it helps a little . There is always next week might recap
Sorry you missed the end because that boob had to come on and bloviate!

I can't do videos too much, it eats up my allotted band width.

Most of the time I don't care how a show ends, when this happens. But like I said, my son and I watch this together. It is one of the few times we get to bond, now that he is 17. When we watch next week, we'll be at a loss as to how The rookie/Nolan was able to prevail in the investigation.

Again, thank you!

https://abc.go.com/shows/the-rookie/episode-guide/season-01/9-standoff