Hold forward when you start. Go into the corrider on the left.
Walk through it without paying attention to the zombies (they won’t get up in time to hurt you).
At the end of the corridor 2 zombies will appear behind the corner.
It isn’t nessecary to kill them, so walk past them and ignore the zombie who stands up from the floor.
Now for something that won’t always work.
You see zombies coming at you. Strafe left and kill the zombie on the left.
Because of this the other will go a little to the left, so you can get past them without them blocking you.
In the space between them and the wall a zombie will appear. Headshot him.

Walk around the corners. You’ll come in a room with some zombies and sometimes some undead priests above you.
Walk straight past the zombies and go right past the corner.
An undead priest is behind the next corner.
Because of that stay close to the right wall, so there’s less chance he’ll hit you.
He will shoot around the corner (sometimes he won’t even shoot) and hide himself behind the corner again.
Walk past the undead priest and you’ll receive a nice boost. Then you come in a small room.
There’s an undead priest on the left, ignore him. Go out of the room and go right(not to the bathroom).
Go left and then left again.

There’s a large room here. Sometimes there are zombies here.
If you’re very fast there will be burning zombies. Go past them and walk on the stairs.
On the stairs is a burning zombie, if you’re fast there’s no zombie.
Shoot him in the head and walk past him without going on fire. Go right past the corner and then straight on.
Go past the left corner and kill the undead priest. Sometimes he won’t die, but only stagger.
Go to the right and if the undead priest is still alive he’ll give you a backboost.

In the room here are zombies and a few burning zombies.
If you’re fast there are no zombies. Go on. At the end of the room you’ll have to go left.
From both corners a zombie will come around. Kill the left one. Go left.
Past the next corner is the pickup.
There are a undead priest and a zombie.
Kill the undead priest and try to get past the zombie without him blocking you.
Get the item and go back(don’t drop off).

Get past the zombie again and go back to the room.
It doesn’t matter if you go on fire here.
At the end of the room 2 undead priest will come. Sometimes they get on fire by a zombie.
If not, kill them. Go left and then right, dodging all the zombies or just shooting them.
Instead of going down the stairs, go right into the room.
Dodge the zombies and drop off the platform.
You’ll see the time portal right in front of you.
Enter it as fast as possible. Sometimes you get a boost, which saves a few tenths.

If you use this strat you should get under 57 easily.
I got 52.6 with this strat.
For myself I made some points where I check the time, to see if it’s worth finishing the run.
See the words in the text which I made bold.
To get under 53, you should be at the first point at 23.0
or around it. You should be at the second point(the pickup) under 41.
If you hold on to these times, you should get under 53 with a normal end.