The Tau- (right upper) decays into an e- (19.4 GeV) identified by its shower in the HPC.
Finally, there is a pair Mu+ (9.8 GeV, left down), Mu- (2.7 GeV, left middle), both identified as minimum ionizing in the HPC and HAB and the Mu+ with hits in both planes of the MUB. The low energy Mu- ranges out in the HAB. The invariant mass of the pair is 6.7 GeV.
The event is interpreted as a Tau+ Tau- accompanied by a photon which gives the Muon pair by "internal conversion".
Ref : this event was published in the Cern Courrier Vol 31 N0 8 (Oct 1991) on p. 8, after the "new effect" observed by ALEPH as an excess of Tau Tau V events had been excluded at the 1991 Conference in Geneva.