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We discuss the observational properties of a remarkably faint triply-imagedgalaxy revealed in a deep z-band ACS observation of the lensing cluster A2218.A well-constrained mass model for the cluster, which incorporates the outcomeof recent Keck spectroscopic campaigns, suggests that the triple system arisesvia a z>6 source viewed at high magnification (~x25). Optical and IR photometryfrom HST and Keck confirms the lensing hypothesis and suggests a significantdiscontinuity occurs in the spectral energy distribution within 9250-9850A. Ifthis break is associated with Gunn-Peterson absorption from neutralhydrogen,6.6<z<7.1 is inferred. Deep Keck spectroscopy conducted using bothoptical and IR spectrographs fails to reveal any prominent emission lines inthis region. However, an IR stellar continuum is detected whose decline below9800A suggests a spectroscopic redshift of z~7. Regardless of the preciseredshift, the source is remarkably compact (<1 kpc) and faint (z=28.0) yet isundergoing vigorous star formation at a rate ~2.6 Mo/yr. An intriguing propertyis the steep slope of the UV continuum implied by the photometry which maysuggest that the source is representative of an early population of galaxiesresponsible for cosmic reionization. Independent verification of these resultsis highly desirable but our attempts highlight the difficulty of studying suchsources with present facilities and the challenges faced in pushing back thefrontiers of the observable universe beyond z~6.5.Comment: 20 pages, paper accepted by the Astrophysical Journa

A Probablez ∼ 7 Galaxy Strongly Lensed by the Rich Cluster A2218: Exploring the Dark Ages