Temporal lobe epilepsy is the most frequent form of drugresistant epilepsy referred to epilepsy surgery centres. The vast majority of lesional cases can be operated on without invasive investigation which is often not the case for non-lesional cases. Invasive investigation in non-lesional cases, however, may lead to unexpected results, as illustrated in the following case report. [Published with video sequence on www. epilepticdisorders. com]