SIGIL

SIGIL is an upcoming episode WAD for Doom and Ultimate Doom that is planned for release in mid-February 2019. It was announced at Doom's 25th anniversary on by its designer, John Romero.

Although billed as a megawad with 18 maps, Romero clarified in an interview that each of the nine single-player levels includes a separate deathmatch arena, making it a standard episode. The levels were created using Doom Builder 2.

Story
SIGIL continues from the fourth episode, Thy Flesh Consumed, with the following story line: "After killing the Spiderdemon at the end of E4M8 (Unto the Cruel), your next stop is Earth — you must save it from hellspawn that is causing unimaginable carnage. But Baphomet glitched the final teleporter with his hidden sigil whose eldritch power brings you to even darker shores of Hell. You fight through this stygian pocket of evil to confront the ultimate harbingers of Satan, then finally return to become Earth’s savior."

- John Romero

Limited editions
Along with the free WAD, two limited edition fan boxes by were announced that are available for pre-order until December 24, 2018, and will ship in April 2019.