diff --git a/run-debug.bat b/run-debug.bat
new file mode 100644
index 0000000..7e89fae
--- /dev/null
+++ b/run-debug.bat
@@ -0,0 +1,22 @@
+@echo off
+REM Run the exe with output captured. Window does not auto-close.
+setlocal
+cd /d "%~dp0"
+echo Running sephiria_inv.exe ...
+echo.
+sephiria_inv.exe > sephiria_inv_console.log 2>&1
+set EC=%errorlevel%
+echo.
+echo === sephiria_inv.exe exited with code %EC% ===
+echo.
+echo --- sephiria_inv_console.log ---
+if exist sephiria_inv_console.log type sephiria_inv_console.log
+echo --- end console.log ---
+echo.
+echo --- sephiria_inv_startup.log ---
+if exist sephiria_inv_startup.log type sephiria_inv_startup.log
+echo --- end startup.log ---
+echo.
+echo Press any key to close this window.
+pause > nul
+endlocal
diff --git a/run.py b/run.py
index 15a4a8e..ba4880a 100644
--- a/run.py
+++ b/run.py
@@ -1,9 +1,13 @@
-"""PyInstaller entry shim.
+"""PyInstaller entry shim with aggressive startup diagnostics.
 
-Wrapped in a top-level try/except so any startup failure is written to
-%LOCALAPPDATA%\\sephiria_inv\\startup.log and surfaced to the user via a
-Tk messagebox when possible. Without this wrapper, --noconsole builds
-exit silently on import-time errors and the user sees "nothing happens".
+Writes a log entry the moment this module is loaded (before any project
+imports). Logs to two locations:
+  1. Next to the exe (sys.executable directory) -- usually the user's
+     Downloads folder; trivially findable.
+  2. %LOCALAPPDATA%/sephiria_inv/startup.log
+
+Either log existing tells us Python started. Neither existing means the
+PyInstaller bootloader died before Python ran (DLL/runtime issue).
 """
 
 from __future__ import annotations
@@ -14,24 +18,57 @@ import traceback
 from datetime import datetime
 
 
-def _log_path() -> str:
-    base = os.environ.get("LOCALAPPDATA") or os.path.expanduser("~")
-    folder = os.path.join(base, "sephiria_inv")
+def _candidate_log_paths():
+    paths = []
+    # 1. Next to the exe (most discoverable for the user)
     try:
-        os.makedirs(folder, exist_ok=True)
-    except OSError:
-        folder = os.path.dirname(os.path.abspath(sys.argv[0])) or "."
-    return os.path.join(folder, "startup.log")
-
-
-def _write_log(msg: str) -> str:
-    path = _log_path()
-    try:
-        with open(path, "a", encoding="utf-8") as fh:
-            fh.write(f"\n=== {datetime.now().isoformat()} ===\n{msg}\n")
-    except OSError:
+        exe_dir = os.path.dirname(os.path.abspath(sys.executable))
+        if exe_dir:
+            paths.append(os.path.join(exe_dir, "sephiria_inv_startup.log"))
+    except Exception:
         pass
-    return path
+    # 2. LOCALAPPDATA / home
+    try:
+        base = os.environ.get("LOCALAPPDATA") or os.path.expanduser("~")
+        folder = os.path.join(base, "sephiria_inv")
+        os.makedirs(folder, exist_ok=True)
+        paths.append(os.path.join(folder, "startup.log"))
+    except Exception:
+        pass
+    return paths
+
+
+def _write_log(msg: str) -> list:
+    written = []
+    stamp = datetime.now().isoformat()
+    for path in _candidate_log_paths():
+        try:
+            with open(path, "a", encoding="utf-8") as fh:
+                fh.write(f"\n=== {stamp} ===\n{msg}\n")
+            written.append(path)
+        except Exception:
+            pass
+    return written
+
+
+def _env_dump() -> str:
+    lines = [
+        f"python: {sys.version}",
+        f"executable: {sys.executable}",
+        f"argv: {sys.argv}",
+        f"frozen: {getattr(sys, 'frozen', False)}",
+        f"_MEIPASS: {getattr(sys, '_MEIPASS', '<none>')}",
+        f"cwd: {os.getcwd()}",
+        f"PATH head: {os.environ.get('PATH', '')[:200]}",
+        f"LOCALAPPDATA: {os.environ.get('LOCALAPPDATA', '<none>')}",
+    ]
+    return "\n".join(lines)
+
+
+# === MODULE-IMPORT BREADCRUMB ===
+# This runs the moment Python loads the entry script. If this never appears
+# in either log, the PyInstaller bootloader failed before Python started.
+_BOOT_LOGS = _write_log("BOOT: run.py loaded\n" + _env_dump())
 
 
 def _show_error(title: str, body: str) -> None:
@@ -40,14 +77,13 @@ def _show_error(title: str, body: str) -> None:
         from tkinter import scrolledtext
         root = tk.Tk()
         root.title(title)
-        root.geometry("760x420")
+        root.geometry("780x460")
         txt = scrolledtext.ScrolledText(root, wrap="word")
         txt.pack(fill="both", expand=True)
         txt.insert("1.0", body)
         tk.Button(root, text="Close", command=root.destroy).pack(pady=4)
         root.mainloop()
     except Exception:
-        # Tk itself is broken; nothing we can show.
         pass
 
 
@@ -56,10 +92,10 @@ def _main() -> int:
         from sephiria_inv.__main__ import main
     except BaseException:
         tb = traceback.format_exc()
-        log = _write_log("IMPORT FAIL\n" + tb)
+        logs = _write_log("IMPORT FAIL\n" + tb + "\n--env--\n" + _env_dump())
         _show_error(
             "sephiria_inv: import failed",
-            f"Failed to import sephiria_inv.__main__\n\nLog: {log}\n\n{tb}",
+            f"Failed to import sephiria_inv.__main__\n\nLogs: {logs}\n\n{tb}",
         )
         return 11
     try:
@@ -68,10 +104,10 @@ def _main() -> int:
         raise
     except BaseException:
         tb = traceback.format_exc()
-        log = _write_log("RUNTIME FAIL\n" + tb)
+        logs = _write_log("RUNTIME FAIL\n" + tb)
         _show_error(
             "sephiria_inv: runtime error",
-            f"Crashed during main()\n\nLog: {log}\n\n{tb}",
+            f"Crashed during main()\n\nLogs: {logs}\n\n{tb}",
         )
         return 12