Sentence:  "Memento" unfolds over 22 scenes—or, more accurately, 22 strands of time, the main strand (in color) moving backward in increments, and another strand (in black and white) going forward, though the two <WSD>overlap</WSD> profoundly. 
Meaning of the word marked with <WSD> tags:  To have an area, range, character or function in common.