Note: on reflection I think that Hadiji Murai’s suggestion (slightly modified) for this section better captures the flow of thought.
A. When – 20 And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, The kingdom of God cometh not with observation: 21 Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you.
B. 22 And he said unto the disciples, The days will come, when ye shall desire to see one of the days of the Son of man, and ye shall not see it. 23 And they shall say to you, See here; or, see there: go not after them, nor follow them. 24 For as the lightning, that lighteneth out of the one part under heaven, shineth unto the other part under heaven; so shall also the Son of man be in his day. 25 But first must he suffer many things, and be rejected of this generation.
C. 26 And as it was in the days of Noe, so shall it be also in the days of the Son of man. 27 They did eat, they drank, they married wives, they were given in marriage, until the day that Noe entered into the ark, and the flood came, and destroyed them all.
C’. 28 Likewise also as it was in the days of Lot; they did eat, they drank, they bought, they sold, they planted, they builded; 29 But the same day that Lot went out of Sodom it rained fire and brimstone from heaven, and destroyed them all. 30 Even thus shall it be in the day when the Son of man is revealed.
B’. 31 In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back. 32 Remember Lot’s wife. 33 Whosoever shall seek to save his life shall lose it; and whosoever shall lose his life shall preserve it. 34 I tell you, in that night there shall be two men in one bed; the one shall be taken, and the other shall be left. 35 Two women shall be grinding together; the one shall be taken, and the other left. 36 Two men shall be in the field; the one shall be taken, and the other left.
A’. Where – 37 And they answered and said unto him, Where, Lord? And he said unto them, Wheresoever the body is, thither will the eagles be gathered together.