MUSE FoV of MACS0138 overlaid on a colour image built from the JWST NIRCam images (the bands used are the same as in Fig. 1). The cyan, red, and yellow lines show iso-surface-brightness contours for the MUSE cube at the wavelengths of the emission lines used to detect the three lensed sources: [OII] emission at z = 0.767 (cyan), Lyman-α emission at z = 3.152 (red) and Lyman-α emission at z = 3.420 (yellow). The two Lyman-α emissions are newly discovered sources strongly lensed by this cluster. We mark the position of the secure multiply lensed images detections (QF = 3) for the three sources (Systems 4, 5, and 6) with a cross.