This is an Infinite Corridor runaround. All the photos are taken from along the north wall of the Infinite Corridor, very nearly within a single vertical plane. So you should plot them within that plane and connect the dots. In addition, some photos have been modified to remove one letter.
| # | Letter | Location |
|---|---|---|
| 1 | 7-008 | |
| 2 | 7-404 | |
| 3 | 3-007 | |
| 4 | 3-221 | |
| 5 | 7-206 | |
| 6 | 7-206C | |
| 7 | 3-211 | |
| 8 | S | 3-305 |
| 9 | C | 3-415 |
| 10 | R | 3-003 |
| 11 | I | across from 10-003 |
| 12 | P | left of 10-250 |
| 13 | T | 10-050 |
| 14 | W | 4-201 |
| 15 | R | 4-215 |
| 16 | I | 4-211 |
| 17 | T | 4-105 |
| 18 | E | 4-003 |
| 19 | R | 4-003 |
| 20 | 4-217 | |
| 21 | next to 4-017 | |
| 22 | 8-204 | |
| 23 | 8-408 | |
| 24 | next to 8-004 | |
| 25 | 8-102 | |
| 26 | between 8-206 & 212 | |
| 27 | between 8-212 & 214 | |
| 28 | next to 8-114 | |
| 29 | next to 8-014 |
The missing letters spell SCRIPT WRITER, which is the first part of the clue phrase. The plot of the photo locations writes out Alvah in script. "Script Writer Alvah" clues the only famous screenwriter named Alvah, Alvah Bessie. So the answer is BESSIE.