This study turns to the pathway of change whereby an originally intransitive manner-of-speaking predicate (e.g. babble, whisper, shout) comes to function in parenthetical clauses as a direct speech reporting predicate. On the descriptive plane, the paper presents a detailed analysis of the recent developments affecting shriek in Early and Late Modern English. The case presented here does not involve the standardly assumed ‘reduction’ of a main clause to an adverbial subject-verb phrase that seems to lack a clausal argument, but rather the augmentation of an intransitive predicate. It does not involve semantic bleaching to a core grammatical meaning such as epistemic hedges or mirative markers or a discursive meaning such as attention-getters, but instead maintains a lexically specific component of manner of speaking. The relevance of the case study is highlighted against the backdrop of broader trends related to transitivization processes with non-prototypical object patterns. The relatively abrupt development is in line with synchronic theories of event lexicalization, which predict that manner roots readily allow for certain argument augmentation patterns that derive a complex event structure. It can be explained on the basis of analogically facilitated co-optation, via a range of semantic and grammatical similarities to other predicates of manner-of-speaking. The study hopes to inspire studies comparing the pathways attested for different semantic subtypes of parentheticals, as well as their interaction, in the near future.