Learners need practice in producing comprehensible output using the language resources at their disposal and already acquired. It has been also well cemented in English as a Foreign Language (EFL) practice that being pushed to produce output allows the production of more accurate and appropriate language. However, speaking courses are probably the most daunting. The major challenge persists with engaging learners into student-to-student interaction and maximizing the talking time. The current paper spots the light on the integration of problem solving situation, built upon the Facebook game “Criminal Case” framework as teacher own produced material to initiate and sustain learners’ talking time during speaking courses in classes described as large. The paper pays close attention to learning opportunities generated by peer interaction compared to teacher-fronted classroom interaction. Using problem solving situations wherein learners are required to play the role of the famous detective Sherlock Holmes and get on the case to solve it proves to generate opportunities for learners to talk, maximize their talking time and build their confidence to use the target language in front of a jury (audience). Last but not least, interactional feedback from their interlocutors and negotiation for meaning push learners to further refine their output and adjust their grammar, vocabulary and pronunciation towards correct utterances.