diff --git a/rust/2023/README.md b/rust/2023/README.md
index 6012455..47ee74c 100644
--- a/rust/2023/README.md
+++ b/rust/2023/README.md
@@ -31,6 +31,7 @@ You try to ask why they can't just use a weather machine ("not powerful enough")
 | [Day 13: Point of Incidence](https://github.com/believer/advent-of-code/blob/master/rust/2023/src/day_13.rs)             | 🌟  |      27300 | 🌟  |           29276 |
 | [Day 14: Parabolic Reflector Dish](https://github.com/believer/advent-of-code/blob/master/rust/2023/src/day_14.rs)       | 🌟  |     108614 | 🌟  |           96447 |
 | [Day 15: Lens Library](https://github.com/believer/advent-of-code/blob/master/rust/2023/src/day_15.rs)                   | 🌟  |     516070 | 🌟  |          244981 |
+| [Day 16: The Floor Will Be Lava](https://github.com/believer/advent-of-code/blob/master/rust/2023/src/day_16.rs)         | 🌟  |       7562 | 🌟  |            7793 |
 
 ## Performance
 
@@ -53,6 +54,7 @@ With the help of [cargo-aoc](https://github.com/gobanos/cargo-aoc) I get automat
 | 13  |  24.87 µs |      17.61 µs |                       |             169.28 µs |
 | 14  |  19.30 µs |      20.22 µs |                       |              23.69 µs |
 | 15  |  19.99 µs |     210.88 µs | - / `-28.20%`         |             241.12 µs |
+| 16  |   1.41 ms |      49.39 ms |                       |              30.33 µs |
 
 \* compared to first solution<br/>
 \*\* slow, didn't benchmark. Value comes from running the solver.
diff --git a/rust/2023/src/day_16.rs b/rust/2023/src/day_16.rs
index 39891b5..29cc9ef 100644
--- a/rust/2023/src/day_16.rs
+++ b/rust/2023/src/day_16.rs
@@ -1,5 +1,9 @@
-//! Day 16
-
+//! Day 16: The Floor Will Be Lava
+//!
+//! Another day, another grid. This time, we'll direct a beam of light
+//! through a grid of mirrors and splitters. The goal is to find the number of
+//! energized tiles, tiles where the beam has been. I enjoyed this one.
+//! Just the right amount of challenge. Not too easy, not too hard.
 
 use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
 use std::collections::{HashSet, VecDeque};
@@ -92,7 +96,8 @@ pub fn input_generator(input: &str) -> Input {
 
 /* Part One
 *
-*
+* Find the number of energized tiles after firing the beam from the top left
+* of the grid.
 */
 // Your puzzle answer was
 #[doc = r#"```
@@ -107,6 +112,8 @@ pub fn solve_part_01(input: &Input) -> usize {
 
 /* Part Two
 *
+* Find the maximum number of energized tiles after firing the beam
+* inwards from all edges of the grid.
 *
 */
 #[doc = r#"```