Crota's End is Destiny's second Raid, introduced as part of the Dark Below expansion, which sees players venture into the Moon to take down the son of Oryx.
Crota's End is probably known as one of the shorter Raids in Destiny, and was originally vulnerable to a range of exploits that allowed daring players to shortcut its most difficult encounters, but a succession of patches has removed that possibility.
This Raid - alongside others in the game - have been brought back at 390 Light as part of the Age of Triumph and the Weekly Featured Raids playlist. There is a Deathsinger Challenge and Crota Challenge now available, as well as other changes mentioned on that page.
Running it at 390 is also a requirement to unlock the new Year 3 Necrochasm.
Destiny: Crota's End guide and walkthrough
Here are the various stages of the Raid in order:
Destiny: Crota's End - Abyss lamp maze and how to deal with Weight of Darkness
How to solo the first loot chest, fight your way past the endless waves of Thrall enemies, cope with the crushing Weight of Darkness debuff, and get to the end of the lamp maze where you claim your first serious Crota's End Raid rewards.
Destiny: Crota's End - How to cross the Bridge, deal with the Swordbearer, Annihilator Totem, and Gatekeeper
How to build the bridge, deal with the Annihilator Totems, and handle the Swordbearer and his counterpart the Gatekeeper before smashing a couple of Ogres to activate the next checkpoint and claim more sweet rewards.
Destiny: Crota's End - The Thrallway and the second raid chest
How to make it through this deceptively difficult curved corridor, and past a pair of overpowered Shriekers who control forcefields that bar your path, evading hordes of Thrall, and hopefully claiming the second Raid chest which lies beyond.
Destiny: Crota's End - Ir Yut the Deathsinger and Liturgy of Ruin
You can't take on Crota until you've defeated Ir Yut, a vicious Wizard whose Liturgy of Ruin song will wipe out your entire fireteam if you don't fight your way to her chamber, then take her out before she can finish it.
Destiny: Crota's End - How to defeat Crota, use the Chalice of Light and survive Oversoul
How to handle this complicated battle in which you won't even be able to heal up unless you're holding a special item called the Chalice of Light. Taking out Crota demands that you defeat a Swordbearer and use his weapon to smash the boss - providing you can lower his shields first, that is.
Deathsinger Challenge, Crota Challenge
How to beat the two Challenges introduced as part of the 390 revamp of the Raid that take place during the final two boss encounters, as well as other tweaks and changes in other areas, including a new Dead Ghost location.