This chapter examines the cross-cultural pursuit of new science during the brief history of the Tarewali Kothi, popularly known as the House of Stars, a modern astronomical observatory built in the 1830s in Lucknow, capital of the former Shīʿa kingdom of Awadh in northern India. Established during the reign of Nawab Naṣīruddīn Ḥaidar (r. 1827-37)under the direction of British experts, the observatory had been operational for less than a decade before it was decisively shut down by the last monarch of Awadh, shortly before the kingdom itself was absorbed by the expanding British-Indian Empire. Cross-examining the political circumstances of the observatory’s brief life and premature closure in the light of the extraordinary history of Indo-Islamic endeavours in astronomy, this chapter offers a more nuanced reading than previous accounts have afforded of the symbolic capital and diplomacy vested in this shared Indo-British pursuit of scientific knowledge. In the microcosm of this early modern Islamic state, the Lucknow Observatory was, arguably, the apex of ʿilm in terms of scientific knowledge production and exchange. The chapter describes a state-of-the-art facility that was distinguished equally by its architecture, not least the hybrid architectural science of its design, and its ‘high-tech’ instrumentation dedicated to practical astronomy. Acknowledging parallel experimentation ongoing in the cosmopolitan culture of pre-colonial Lucknow with the modern styles of European architecture, the observatory building and institution is also interpreted as a site of cultural intersection and diplomatic exchange, where the higher ideal of pure science was, at least briefly, shared. While the decommissioned observatory building was ultimately re-purposed for other more worldly uses, the original joint venture in scientific discovery (for which the observatory had been built) was deemed to be a failure. In the geopolitical context in which the Indo-Islamic world had been enveloped by European imperialism, the focus of astronomy and allied sciences of observation had shifted from the heavens to the more terrestrial purposes of territorial mapping and control.