(adjective) of, relating to, or constituting a portent / (adjective) eliciting amazement or wonder; prodigious / (adjective) being a grave or serious matter / (adjective) self-consciously solemn or important; pompous / (adjective) ponderously excessive
As she came to a particularly dramatic passage, where the hero was about to encounter some strange, perhaps fatal danger, her voice would slow down, her words would be spaced portentously