The goal of future neutrinoless double beta decay experiments is to establish whether neutrino is its own antiparticle by detecting an ultra-rare decay process with a half life that may be more than 10^27 years.  Such a discovery would have major implications for cosmology and particle physics, but requires large detectors with backgrounds that are controlled to below 1 count per ton per year. This represents a formidable technological challenge.  I will discuss an approach being developed within the NEXT collaboration: high pressure xenon gas time projection chambers augmented single molecule fluorescent imaging-based barium tagging. This combination of techniques from biochemistry, super-resolution microscopy, organic synthesis and nuclear physics may enable the first effectively background-free, ton-scale neutrinoless double beta decay detection technique.