Give both rooms the same 1-9 symbol index, send one side by speech and the return side as separated light-flash groups, then submit both five-slot rows.
Find the yellow-green two-room building around 3825, 1930, north of Green Tower at the end of the long green ramp. Before entering, number both nine-piece symbol sets in the same left-to-right order and confirm what 1 and 9 mean. Put one player in each room. The right-room player uses the voice channel to tell the left player the indices missing from the left five-slot display. The left player fills them, then returns the indices missing on the right by flashing the red signal N times per index, with a three-second pause between groups. Send groups in the right display’s open-slot order. The right player fills those pieces. When both five-slot rows are complete, the left player presses the red submit control below the black screen; confetti and the released Green Tower piece confirm success.
Travel north from Green Tower to approximately 3825, 1930. A long green approach ramp leads directly to a yellow-green building with two barred rooms. Each side contains a five-slot display and nine hand-drawn symbol pieces; one side also has the red signalling control beneath a black screen.
From Green Tower, travel north toward 3825, 1930 and take the long green ramp to the yellow-green barred building. Check that both halves contain hand-drawn symbol pieces and five answer slots.
The team is at one structure with two separated rooms, not at a single-room nine-piece symbol puzzle.
Drop any loose gear that may be removed by the entrance, then send the assigned players through opposite barred entries. Do not put both active players on one side.
One player owns the left display and one owns the right display; both can reach their local pieces and controls.
Each player labels the five answer positions L1-L5 or R1-R5 from left to right and notes which positions are already visible and which are blank. Report only blank positions so accepted information is not overwritten.
Both players can name every open slot by side and position before any piece is moved.
Compare the two nine-piece sets before relying on numbers. Both players count in the same direction and verify candidate 1 plus candidate 9 by a short visual nickname. If those endpoints disagree, reverse one index now.
Saying any number from 1-9 identifies the same drawing in both rooms.
The right-room player reads the left display’s missing pieces and speaks them in open-slot order: first say the slot, then the candidate index, such as “L2 equals 4.” The left player repeats the pair once and inserts that indexed piece.
Every blank left slot is filled and its owner can read back the full L1-L5 row.
The left player takes the first blank right-side position and taps the red signal exactly N times for candidate N. Leave the light off for three seconds, then send the next blank position. The right player counts aloud, writes the number, and places a piece only after the pause confirms the group ended.
The right player has one separated count for each originally blank R slot; no two groups were added together.
Read L1-L5 and R1-R5 separately. Check each inserted piece against the written shared index, especially any near-mirrored drawings. If one position is uncertain, resend only that slot rather than repeating the entire message.
Both displays contain five pieces and neither player has an unresolved count or candidate.
The left-room player presses the red control below the black screen once. Do not dismantle either row while it checks. On success, leave through the opened route and collect the released Green Tower control-panel piece.
Confetti appears, the room unlocks, and the team leaves with the Green Tower piece.
Use one player per room. Each person writes their own open slots and received indices; the left player also owns the flash signal and final submit control.
Keep one receiver in each room. Extra players can verify candidate drawings or count flashes, but only the designated receiver inserts pieces so duplicate inputs do not disturb the rows.