+\part[Variations --- Tiered vs.\ Tierless Programming]{Transformation\\[2ex]\smaller{}Tiered vs.\ Tierless Programming}%
+\label{prt:tvt}
+\subfile{tvt/tvt} % Could Tierless Languages Reduce IoT Development Grief?
+
+\bookmarksetup{startatroot} % descend back out of the previous part
+\addtocontents{toc}{\bigskip}% Insert some whitespace to make the TOC better
+\subfile{concl/conclusion}