The chapter
Simply A disciple admires the temple stones on the way out, and is told not one will be left on another. Four of them ask privately when this will happen and what the sign will be, and the rest of the chapter is the answer.
Context The answer spends more time refusing the question than meeting it. He warns four times about being led astray, tells them wars and earthquakes are not the end, and says plainly that nobody knows the day or the hour, not the angels and not the Son, only the Father. The last word of the chapter, said to everyone and not only to the four, is watch.
Verses 5-13
Simply Most of what he describes first is ordinary catastrophe: false claimants, wars, earthquakes, famines. He calls these the beginning of birth pains, which is to say the start of something and not the end of it.
Context Then it turns personal and hard. They will be handed over to councils and beaten in synagogues, brother will hand over brother, and they will be hated for his name; and in the middle of that he tells them not to rehearse a defence, because what they say will be given to them. The endurance he asks for is to the end, without a date attached to it.
Verses 14-23
Simply At the centre is an instruction to run: when you see the abomination of desolation standing where it should not, leave Judea for the hills, do not go back into the house, do not turn back for a cloak. He says it is worst for women who are pregnant or nursing, and tells them to pray it is not winter.
Context The phrase is Daniel's, and Mark names him, then breaks off to address whoever is reading, which he does nowhere else in the gospel: let the reader understand. What follows is a warning against exactly the certainty the chapter is often read for. If anyone tells you the Christ is here or there, do not believe it, because false christs and false prophets will produce signs.
Verses 24-31
Simply The sun darkened, the moon without light, the stars falling: the language of the prophets for a world coming apart. Then the Son of Man is seen coming in clouds, and gathers the chosen from the four winds.
Context Coming with the clouds is Daniel's picture too, of one like a son of man. The fig tree comes back here as a parable rather than a curse, and for the opposite purpose: leaves mean summer is close. Then two sentences that have been argued over ever since, that this generation will not pass away until all these things happen, and that his words will not pass away though heaven and earth do.
Verses 32-37
Simply He ends by saying nobody knows when: not the angels, not the Son, only the Father. What is asked for instead is a doorkeeper's job, staying awake because the hour is unknown.
Context The four times he lists are evening, midnight, cockcrow and morning, and three of them are the timestamps of the next two chapters: evening when he sits down with the twelve, the second crow of the rooster in the courtyard, and morning when the council hands him over. The chapter closes by widening the audience: what I tell you, I tell everyone.