We report a detection of an absorption line at \sim 44.8 ~ { } \AA in a > 500 ~ { } ks Chandra HRC-S/LETG X-ray grating spectrum of the blazar H 2356-309 . This line can be identified as intervening C V -K \alpha absorption , at z \approx 0.112 , produced by a warm ( \log T = 5.1 ~ { } K ) intergalactic absorber . The feature is significant at a 2.9 \sigma level ( accounting for the number of independent redshift trials ) . We estimate an equivalent hydrogen column density of \log N _ { H } = 19.05 ~ { } ( Z / Z _ { \odot } ) ^ { -1 } ~ { } cm ^ { -2 } . Unlike other previously reported FUV/X-ray metal detections of warm-hot intergalactic medium ( WHIM ) , this CV absorber lies in a region with locally low galaxy density , at \sim 2.2 ~ { } Mpc from the closest galaxy at that redshift , and therefore is unlikely to be associated with an extended galactic halo . We instead tentatively identify this absorber with an intervening Warm-Hot Intergalactic Medium filament possibly permeating a large–scale , 30 Mpc extended , structure of galaxies whose redshift centroid , within a cylinder of 7.5 Mpc radius centered on the line of sight to H 2356-309 , is marginally consistent ( at a 1.8 ~ { } \sigma level ) with the redshift of the absorber .