What happens when Chinese is shaped by centuries of contact with Mongolic, Tungusic, Turkic, and Tibetic languages? This volume explores this question through striking case studies of lects like Tangwang and Wutun, where Chinese exhibits unexpected features such as OV word order, case suffixes, and restructured verbal morphology. Drawing on rare fieldwork data, this volume reveals how deep multilingual interaction transforms grammatical systems. It offers a unique contribution to the study of language change, typology, and contact linguistics—essential reading for anyone interested in how languages evolve in complex sociolinguistic environments.