Blocking the backstop Sentinels

Posted May 11th 2020

Associated movies

  • BCM426 - Heroic; Blocking the backstop Sentinels (7:35)
Hold it right there fellas!

At the start of the level you arrive in an opening, and there are two more adjacent. When you advance a little, Cortana talks a while and then there's a prompt saying "Make your way to the bridge". About 12 seconds after it disappears, two Sentinels spawn below two of the openings - namely the one you arrived at and the one at the other end - then two more spawn. I'll call these the 'backstop' Sentinels as they act as a sort of backstop to your arrival.

Following scripted behaviour, they ascend in their two waves then sedately cruise into the passage to which the openings lead, and get hostile if you're still around. Evidently Bungie intended them to give you a bit of a surprise if you're dawdling, rather than having advanced into the access way around the corner.

Wedged at the first bottleneck

If you were never much of a one to dawdle, you might've been unaware that these Sentinels even existed. They actually came as a surprise to me recently, when I was working on descending from the ship, and noticed them spawning after I'd descended. Either I'd never encountered them before, or else I'd just forgotten about them. Anyway, it turns out that they're quite good for amusement. One bit of fun you can have is to block their advance, which is trivially easy to do.

Convenient pre-spawn checkpoint

For repeatedly having fun blocking them, you should first get a delayed checkpoint just before they spawn. That's easy. After the prompt disappears, do 6 quick jumps (you can 'auto-jump', i.e. keeping the jump button down) and you should get a fairly ideal checkpoint. The checkpoint is due about 2 seconds after the prompt vanishes, but your last few jumps delay it.

Getting a bit frisky eh?

Aspects of the fun

There are various places you can stand to block a pair of Sentinels (or just one, if you care to destroy the other in advance), and by doing so you can get a very close view of them, from various angles. My movie BCM426 provides a load of examples, together with assorted destructive fun. You can deal with either of the two pairs. I haven't noticed any difference between them in regard to blocking.

One particular thing you can try for is to get a pair wedged together at a bottleneck, essentially blocking themselves once you stand clear. Better be careful though; you can easily end up getting wedged in yourself!

Sometimes a blocked Sentinel will wake up from its passive state and attack, something they'd normally only do after reaching the passage. I haven't noticed any clear pattern to this but I can say a few things. Firstly, destroying one of a pair sometimes causes the other to attack. Secondly, it's unusual to get a double attack.