L’Invisible is a 2017 opera by Aribert Reimann.
[1] The French libretto by Reimann is a condensation of three short plays by Maurice Maeterlinck; L'Intruse, Intérieur and La Mort de Tintagiles, into a single act opera.
The "invisible" in each part is death, first as a supernatural force, then as tragic news, then in the person of a murderous queen.
[2]