Although discussion about connecting Chinese railways to Nepal borders first surfaced in the year 1973, it could not make any headway until the political change of 2006 in Nepal, when the idea of linking Tibet with Kathmandu resurfaced again. However, political instability in Nepal further thwarted it, at least until Nepal faced the Indian blockade in 2015 and had to look for ways to diversify its trade and transit. Thus, for Nepal, China’s railways offer an escape from its dependence on India for trade and transit. But, for Beijing, it offers a strategic gateway to enter South Asia, which is India’s conventional sphere of influence. Although Nepal and its northern neighbor China have agreed to connect Nepal’s capital Kathmandu with the Tibetan Autonomous Region of China through railways, the materialization of such a game-changer is not free from challenges. Against the same backdrop, the objective of this study is to discover various challenges faced by the trans-Himalayan railways including political, bureaucratic, economic, and environmental challenges, and to concurrently identify how the geopolitical challenge tops the list, halting Nepal’s ambition to ‘bridge’ India and China and instead aggravating the possibility of becoming a burden to both the Asian giants. While the available literature on China and South Asia is mostly concentrated on Belt and Road (BRI) projects, ‘debt trap’ narratives, and geopolitical rivalry between India and China, this study would be a new attempt to understand how China’s aim to get connected with South Asia via land is not free of impediments. Using the qualitative method, this study reviews the geopolitical challenges confronted by the trans-Himalayan railway in the context of territorial disputes between India and China in the Himalayan region and the U.S.-Indian strategic partnership to contain the rise of China and its ambitious connectivity projects.