diff --git a/challenges/2024/04-ceresSearch/README.md b/challenges/2024/04-ceresSearch/README.md
new file mode 100644
index 0000000..adb5ed9
--- /dev/null
+++ b/challenges/2024/04-ceresSearch/README.md
@@ -0,0 +1,5 @@
+# [Day 4: Ceres Search](https://adventofcode.com/2024/day/4)
+
+Part two is:
+* less than 1976
+* also, somewhat obviously, less than 1978
\ No newline at end of file
diff --git a/challenges/2024/04-ceresSearch/main.py b/challenges/2024/04-ceresSearch/main.py
new file mode 100644
index 0000000..aa456e2
--- /dev/null
+++ b/challenges/2024/04-ceresSearch/main.py
@@ -0,0 +1,81 @@
+import sys
+import gridutil.grid as grid
+import gridutil.coord as coord
+
+
+def parse(instr: str) -> grid.Grid:
+    return grid.parse(instr.upper())
+
+
+def one(instr: str):
+    wordsearch = parse(instr)
+
+    seq_starts = list(
+        map(lambda x: x[0], filter(lambda x: x[1] == "X", wordsearch.items()))
+    )
+    detected_sequences = set()
+
+    for start_pos in seq_starts:
+        for xdir in [-1, 0, 1]:
+            for ydir in [-1, 0, 1]:
+
+                if xdir == 0 and ydir == 0:
+                    continue
+
+                delta = coord.Coordinate(xdir, ydir)
+
+                ok = True
+                for i, v in enumerate("XMAS"):
+                    if not ok:
+                        break
+
+                    g = wordsearch.get(coord.add(start_pos, coord.mult(delta, i)), "-")
+                    ok = g == v
+
+                if ok:
+                    detected_sequences.add((start_pos, delta))
+
+    return len(detected_sequences)
+
+
+def check_cross_adjacents(s: str) -> bool:
+    return s == "SM" or s == "MS"
+
+
+def two(instr: str):
+    wordsearch = parse(instr)
+
+    seq_starts = list(
+        map(lambda x: x[0], filter(lambda x: x[1] == "A", wordsearch.items()))
+    )
+    detected_sequences = set()
+
+    for start_pos in seq_starts:
+
+        a = wordsearch.get(coord.add(start_pos, (-1, -1)), "") + wordsearch.get(
+            coord.add(start_pos, (1, 1)), ""
+        )
+        b = wordsearch.get(coord.add(start_pos, (-1, 1)), "") + wordsearch.get(
+            coord.add(start_pos, (1, -1)), ""
+        )
+
+        if check_cross_adjacents(a) and check_cross_adjacents(b):
+            detected_sequences.add(start_pos)
+
+    return len(detected_sequences)
+
+
+def _debug(*args, **kwargs):
+    kwargs["file"] = sys.stderr
+    print(*args, **kwargs)
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2 or sys.argv[1] not in ["1", "2"]:
+        print("Missing day argument", file=sys.stderr)
+        sys.exit(1)
+    inp = sys.stdin.read().strip()
+    if sys.argv[1] == "1":
+        print(one(inp))
+    else:
+        print(two(inp))
diff --git a/challenges/2024/04-ceresSearch/tests.json b/challenges/2024/04-ceresSearch/tests.json
new file mode 100644
index 0000000..9c92e6f
--- /dev/null
+++ b/challenges/2024/04-ceresSearch/tests.json
@@ -0,0 +1,14 @@
+{
+    "1": [
+        {
+            "is": "18",
+            "input": "MMMSXXMASM\nMSAMXMSMSA\nAMXSXMAAMM\nMSAMASMSMX\nXMASAMXAMM\nXXAMMXXAMA\nSMSMSASXSS\nSAXAMASAAA\nMAMMMXMMMM\nMXMXAXMASX\n\n"
+        }
+    ],
+    "2": [
+        {
+            "is": "9",
+            "input": "MMMSXXMASM\nMSAMXMSMSA\nAMXSXMAAMM\nMSAMASMSMX\nXMASAMXAMM\nXXAMMXXAMA\nSMSMSASXSS\nSAXAMASAAA\nMAMMMXMMMM\nMXMXAXMASX\n\n"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/challenges/2024/README.md b/challenges/2024/README.md
index 3d13da2..735acb0 100644
--- a/challenges/2024/README.md
+++ b/challenges/2024/README.md
@@ -4,7 +4,7 @@ Solutions to the [2024 Advent of Code](https://adventofcode.com/2024)!
 
 ---
 
-Total stars: **6 ★**
+Total stars: **8 ★**
 
 ![Benchmark graph](./benchmark-graph.png)
 
@@ -16,4 +16,5 @@ A day denoted with a star means it has a visualisation.
 |-------------------------------------|--------|----------------------|-------|
 | 01 - Historian Hysteria             | ★ ★   | Python               | The reading comprehension was the hardest part of this. |
 | 02 - Red-Nosed Reindeer             | ★ ★   | Python               ||
-| 03 - Mull It Over                   | ★ ★   | Python               | The first instance of Advent of Parsing this year! |
\ No newline at end of file
+| 03 - Mull It Over                   | ★ ★   | Python               | The first instance of Advent of Parsing this year! |
+| 04 - Ceres Search                   | ★ ★   | Python               | When it says a cross, it does not mean a plus. |
\ No newline at end of file
diff --git a/challenges/2024/benchmark-graph.png b/challenges/2024/benchmark-graph.png
index 9b0aa14..a0f44ed 100644
Binary files a/challenges/2024/benchmark-graph.png and b/challenges/2024/benchmark-graph.png differ
diff --git a/challenges/2024/benchmarks.jsonl b/challenges/2024/benchmarks.jsonl
index 66053fb..4b1a70b 100644
--- a/challenges/2024/benchmarks.jsonl
+++ b/challenges/2024/benchmarks.jsonl
@@ -4,3 +4,5 @@
 {"day": 2, "part": 2, "runner": "py", "min": 0.02489948272705078, "max": 0.0319674015045166, "avg": 0.026371052265167238, "n": 100}
 {"day": 3, "part": 1, "runner": "py", "min": 0.02116227149963379, "max": 0.03153491020202637, "avg": 0.022634525299072266, "n": 100}
 {"day": 3, "part": 2, "runner": "py", "min": 0.02115607261657715, "max": 0.03121805191040039, "avg": 0.022722084522247315, "n": 100}
+{"day": 4, "part": 1, "runner": "py", "min": 0.17342424392700195, "max": 0.3778045177459717, "avg": 0.18848238706588746, "n": 100}
+{"day": 4, "part": 2, "runner": "py", "min": 0.05280470848083496, "max": 0.06299543380737305, "avg": 0.05627016305923462, "n": 100}