Also Known As:- What Have You Done to Solange?
- ¿Qué habéis hecho con Solange?
- Das Geheimnis der grünen Stecknadel
- Mais... qu'avez vous fait à Solange?
- Mannen i svart
- Que Fizeram a Solange?
- Solange
- Terror in the Woods
- The School That Couldn't Scream
- The Secret of the Green Pins
- Ti apegine i Solange?
- Tromos sto parthenagogeio
- Vahset - Solange'e ne yaptiniz?
- Viasmos sto parthenagogeio
- Who Killed Solange?
- Who's Next?
- Massimo Dallamano
- Bruno Di Geronimo
- Massimo Dallamano
- Peter M. Thouet
- Edgar Wallace novel "The Clue of the New Pin"
- Fabio Testi ... Enrico 'Henry' Rosseni
- Cristina Galbó ... Elizabeth Seccles (as Christine Galbo)
- Karin Baal ... Herta Rosseni
- Joachim Fuchsberger ... Inspector Barth
- Günther Stoll ... Professor Bascombe
- Claudia Butenuth ... Brenda Pilchard
- Camille Keaton ... Solange Beauregard
- Maria Monti ... Mrs. Erickson
- Giancarlo Badessi ... Mr. Erickson
- Pilar Castel ... Janet Bryant
- Giovanna Di Bernardo ... Helen Edmonds
- Vittorio Fanfoni ... Enrico's friend
- Marco Mariani ... Father Webber
- Antonio Casale ... Mr. Newton (as Antony Vernon)
- Emilia Wolkowicz ... Ruth Holden (as Emilia Wolkowich)
- Daniele Micheletti ... Mr. Bryant
- Antonio Anelli ... Father Herbert
- Rainer Penkert ... Mr. Leach, the headmaster
- Carla Mancini ... Susan, girl in Enrico's class
- Joe D'Amato ... CID officer w / The Daily Telegraph
- John Gayford ... Joseph Kane
- Maria Michi ... Brenda's mother
- Alfred Vohrer ... Edgar Wallace (voice) (archive footage)
