Anytime the Metropolitan Opera puts on a new production of Wagner’s “Der Ring des Nibelungen,” you better believe that it is a major event.

The tetralogy will reappear in 2018-19 for the first time since the 2013 season, and as might be expected, there aren’t very many opportunities to check it out.

So here is a rundown of the essential facts that you must keep stock of to check out this massive masterwork next season.

The Dates

For starters, there are three cycles, but “Das Rheingold” and “Die Walküre” will get extra performances outside of the sequence.

“Das Rheingold” gets the first performance of all on March 9, 2019. Ensuing performances take place on March 14, April 29, and May 6.

“Die Walküre” gets five performances starting on March 25 and 30 with more showcases to come on April 25, 30, and May 7.

“Siegfried” appears on April 13, May 2, and May 9 while “Götterdämmerung” will take the stage on April 27, May 4, and May 11.

The Casts

The cast for “Das Rheingold” is as follows: Wendy Bryn Harmer appears as Freia, Jamie Barton plays Fricka, Karen Cargill takes on Erda, Norbert Ernst is Loge, Gerhard Siegel is Mime, Tomasz Konieczny is Alberich, Günther Groissböck is Fasolt, and Dmitry Belosselskiy is Fafner. Greer Grimsley takes on performances as Wotan in March while Michael Volle appears on April 29 and May 6.

The two men play the switcheroo again as Wotan for their respective runs of “Die Walküre” as well. Volle headlines the showcases on April 30 and May 7 while Grimsley gets his turn during the first three performances. Otherwise the cast that includes Christine Goerke (Brünhilde), Eva-Marie Westbroek (Sieglinde), Jamie Barton (Fricka), Stuart Skelton (Siegmund), and Groissböck (Hunding) sing all the performances of their respective roles.

Many of the same cast members return to their respective roles in “Siegfried” (Volle sings all three performances) though the title role will be alternated between Stefan Vinke and Andreas Schager. Vinke gets performances on April 13 and May 9 while Schager gets the one on May 2.

Eric Owens sings his first Hagen in a massive cast that includes Evgeny Nikitin as Gunther, Edith Haller as Gutrune, and Sarah Connolly as Waltraute. Again, Schager and Vinke alternate the role of Siegfried, though Vinke gets just one showing on May 11 while Schager sings on April 27 and May 4.

Phillippe Jordan will conduct every single performance.