atlas (bound collection of maps)

a road or path, (often) a highway / a course, an itinerary of stops, as for a bus / a path or course for information / a path or course for goods in a transaction / (video games, storytelling) storyline

(mathematics) a root (as in a square root) / (linguistics) an etymological root / (music) root note in a chord

open (intransitive verb)

a map (visual representation of an area)

to open / to begin an event

to open, lift, uncover, unpack / to bloom / to start, open (a store)

travel, a trip, a journey, a voyage, a tour

back channel

curtain