People with complex information needs are for example Humanities researchers, who need advanced search engines to investigate their research questions. Much can be gained by combining research datasets, reusing tools and serendipitously discovering new insights for further research. Humanities researchers have different (large-scale) research datasets and tools, which are described differently with metadata. We present a highly interactive advanced search engine for Humanities researchers that semantically converges differently structured metadata records from different collections and institutions. It has features that support serendipitous and focused search in context based on the structure of the metadata used. This single system serves Humanities researchers by allowing them to search interactively across yet unexplored (research) data, discover patterns, locate relevant data for new insights, and find existing tools that could provide novel use cases.