The most devastating and heartwrenching thing about the Last Supper is that Jesus knew that His disciples, His friends will betray him. Still, He washes their feet, and still, He gives them His blood and body.
And this is the tragedy of God, that He dies for those who are not just abstractly imperfect and who have done something nasty, He dies for people who betray Him daily.
He says: here, I give you the Kingdom, to you who betray me, here, I give you the Kingdom, I've bought it for you with my blood.
And this is the tragedy of Man, that He must carry all that sorrow in Himself, in His human body (it is unthinkable for humans, impossible). And the sorrow evidently eats Him alive, He tries to comfort Himself in His last hours, so He spends them with apostles. Jesus is eager to find a shoulder to lay His head on, a shoulder to cry on. But He has no one to share the sorrow with who won't betray Him, He is alone in that. He has no one who would even understand His sacrifice, oh no, no one would even care to stay awake with Him.
So He turns to the Father, He prays and prays and in His last moments, it's only the Son and the Father who are left. But even the Father leaves Him. Everyone leaves Him, Everything leaves Him. Candles out, it's dark, the Saturday will be quiet.