The Invisible Assassin

The most powerful influence in any room is often the one nobody notices: tone.

Before you have time to weigh the words, tone is already shaping whether an interaction feels safe, believable, threatening or true. Tone can make a stranger seem trustworthy, a leader sound convincing, a friend’s voice bring relief, or a politician's speech stir loyalty or fear.

In The Invisible Assassin, forensic psychologist Dr Nashater Deu Solheim reveals how tone, working beneath conscious awareness, affects the nervous system and shapes judgement, relationships, and decisions. Tone can build trust, calm conflict, and bring people together. It can also close minds, distort meaning, and lead us towards choices we believe are entirely our own.

Not only are we affected by tone, we are also emitting it all the time. In our homes, workplaces, and public life, the signals we pass between us help co-create the trust or tension, openness or division, that follows.

Drawing on psychology, neuroscience, negotiation, and decades of studying behaviour, influence, and performance — including her most unexpected classroom, a dolphin pool where there were no words and nowhere to hide — Dr Deu Solheim makes this hidden force visible. Through the 4 Tonal Signals and Attunement Circle, she shows how to read what is shaping you, resist what works against you, and choose what you co-create.

Once you can see the signal beneath the words, you cannot unsee it. And everything changes.