The first sub-70 minute non-interacting WD-BD system: EPIC212235321

S.L. Casewell acknowledges support from the University of Leicester Institute for Space and Earth Observation and I.P Braker acknowledges support from the University of Leicester College of Science and Engineering. S.G. Parsons acknowledges the support of the Leverhulme Trust. Support for this work was provided by NASA through Hubble Fellowship grant HST-HF2-51357.001-A, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5- 26555. This work is based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Minist´erio da Ciˆencia, Tecnologia, Inova¸c˜aos e Comunica¸c˜aoes (MCTIC) do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). This paper also uses observations made at the South African Astronomical Observatory (SAAO). The WHT is operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof´isica de Canarias. Also based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 177.A-3011(A,B,C,D,E,F,G,H,I,J), and 099.D-0252.