Follow Mike Birbiglia from Providence, R.I. to Washington, D.C. as he builds jokes based on personal truths, mixing comedy with revelations and anecdotes from family and his fellow comedians.

ZachexplorestheunpredictableandterrifyingphenomenonofSinkholestodeterminejustwhatcausesthem.HevisitsaFloridamanwhosebrotherwaskilledwhentheirfamilyhomewasliterallyswallowedwholebytheEarthaswellasaseriesofsinkholesthatareformingaseriesofcavesrightbelowthehousesofaquaintsuburbanneighborhood.Whethertheybeapartofsomebiblicalprophecyorfurtherevidenceofmankind’seffectonourplanet,he’salarmedtodiscoverthatallthesame,theycanstrikeanywhereintheworld,atanytime.