Sebastian has written several stage plays, among them The Power of Love, Love Hurts and Time After Time, which together now form the Love Trilogy and each of which individually reached the shortlist, long list and final ten respectively of Soho Theatre's Verity Bargate Award in separate years; Elder Latimer is in Love (Arcola Theatre, London, 2009) and Top Story (The Old Vic Tunnels, London, 2013), both directed by Adam Berzsenyi Bellaagh. His next play, Baur au Lac, is currently in development with Park Theatre, London.
Earlier plays of Sebastian's were seen on the London and Edinburgh fringe and include QED, Sisters (which he also directed), and All the World, in which he also acted and which he codirected with Mehmet Ergen. Sebastian also wrote the book for the musical Alvaro's Balcony (music & lyrics by Jonathan Kaldor), which premiered at the Landor Theatre in London in 2008.
Sebastian has written and directed two short films: Twenty-Six Takes on Life without Allen, which was screened at festivals in Chicago, Los Angeles, London, Lisbon and Padua, and The Study of Bunkers & Mounds in a Temperate Climate (Relatively Speaking) which was screened in the official selection of the International Film Festival Locarno 2007.
His first feature film as an actor, writer and director,The Hour of Living, was nominated ‘Best Feature’ at the 2012 Basel Film Awards in Switzerland, and has been shown at festivals in Italy, New York and Australia.
After his training at Drama Studio London, Sebastian worked in various touring productions, playing, among others, Mephisto in Faust and Möbius in Die Physiker as well as a range of parts on the London and Edinburgh Fringe, with directors including Michael Cabot and Phil Willmott.
Together with Charlie Bicknell, Sebastian formed the music comedy act Kissing the Goldfish, which appeared at several Edinburgh Fringe Festivals, as well as doing festivals and individual gigs in Australia, Hong Kong, Belgium, France and Switzerland.
Sebastian has written a novel, Angel, and he is co-author of Genius Planet, a collaboration with Professor Ludger Hovestadt and Vera Bühlmann of ETH Zürich which postulates a radical roadmap from energy scarcity to abundance and is due for publication in 2014.