Dr Horn

Dr Horn is the main protagonist (or, depending on your perspective, antagonist) in this story. This was evident from the very beginning as Dr Horn's name was found on many of the whiteboards, one of which contained a cipher. On the whiteboards, Dr Horn was also complaining about people stealing and eating his pizzas, which linked him to the mysterious The Pizza is a LIE! messages scribbled on the wall beside the first code, and in many other hidden locations. "They stole the lie, as if that matters to me, HALOS is far too complete to stop now. They can't hide there, not now, not now I have this, this holds the key to all things... they CAN'T hide from me. I will follow them, I'll set up a link and this to remind me."

- Dr Horn

Information

 * Dr Horn is the in-game alias for Chris Horn, also known as Stormseeker, one of the level designers for Black Mesa.
 * From his homepage - linked to from the Team Members section of blackmesasource.com, we found a link to terminal.blackmesasource.com by manually entering the Konami code as hinted at in Code A.
 * He has an office and a locker in the Questionable Ethics chapter. The office is located in the left wing of Lab D on the second floor of the Advanced Biological Research Facility (ABRF). He shares office space with Dr Foreman.
 * His field of expertise is primarily quantum optronics.
 * He is listed as one of the four founders of the Advanced Biological Research Facility on a sign in the Biodome Complex lobby. The other founders listed are Dr Stone, Dr Welsh and Dr Foreman.
 * He has a shack in-game in the Surface Tension chapter.
 * He has a secret lair in Xen (Gonarch's Lair).

Location
Dr Horn's current location is currently unknown. He is believed to have stepped through the mysterious gate in the secret lair in Xen. The gate is currently broken. Where the gate led to is still a mystery.

Prior to the discovery of the secret lair, a hidden inaccessible area was found in Xen (map bm_c4a1b; setpos -2757 -887 10996;setang 26 133 0) where the following items were found: a makeshift desk, Dr Horn's desk name plate, pizza, dinner plate, power module, light, geiger counter (hidden in the ground). The Pizza is a LIE! graffiti can also be found nearby.

A few instances of what may or may not be his dead body have been found in the game:
 * His name was found in map entities associated with the scientist who is killed (gibbed) in a lab in QE in the scene where the tau cannon overcharges. This fact was added to this page by wiki editor who wrote: "it looks like he's dead in the tau cannon QE room. the gibs belong to him". Later, User:Dr Horn edited the page, adding "(or do they...)" to the line. User:Dr Horn has been confirmed to be an account under Stormseeker's control on this wiki.
 * Two dead bodies in HEV suits with Dr Horn's nametag can be found in his secret lair. One of the bodies lie face up, the other face down. It is believed that this is somehow related to the idea of quantum superposition.
 * Another dead scientist HEV suit with Dr Horn's nametag has been found in the second map of Inbound (bm_c0a0b) near a The pizza is a LIE! graffiti, in one of two towers near the room through which a canyon vista can be seen during the tram ride (see comment section below). This appears to have been added to the game with the first beta of the 1.0 release of Black Mesa.
 * More suits/bodies with Dr. Horn's nametags have been found in the Definitive Edition. The most interesting locations are in the background12 and background16 maps, where his suit appears alongside a constellation of four other suits, whose nametags spell out "MYON". Another interesting location is a new secret room in bm_c2a2b, where we find a whiteboard with bloody handprints forming the letter A. See the Definitive Edition clues page for more information. Dr. Horn's suit has also been found in the maps background13, bm_c1a1d, and bm_c3a1b.
 * Regarding Dr. Horn's dead body being found in various locations, Stormseeker commented:
 * i have no idea why i keep turning up dead all over the place, seems mysterious
 * i blame @[LD] Anthony Stone
 * hes bound to be behind them
 * >_>


 * In the Xen Museum, an official mod released on April 26, 2021, his suit was found in the 'S4 - Site 8 "Gonarchs Lair"' biome. The suit here has an entity name of "drhornsuit2" in the map file. This is reminiscent of the entity names of the two suits found in Dr. Horn's Xen Lair, which were "drhornsuit1" and "drhornsuit2". Why the suit in the Xen Museum was given this particular name is unknown. In addition, an office with Dr. Horn's desk nameplate was found in the same area, along with a whiteboard with bloody handprints forming the letter A, just like in bm_c2a2b.

Hidden Message (speculation)
If you look at the Diploma The first capitalized letter of each word gives you UOC CH PD AQO CEO

Entering this into an online anagrammer gives, as one of its results, “quo cap code hoc” Which, on Google’s Latin to English site translates from latin to English as “This is the cap code”

Moving the phrase around a bit as “quo hoc cap code” results in “This chapter of the code”