Context : The formation of cosmic structure culminates with the assembly of galaxy clusters , a process quite different from cluster to cluster .

Aims : We present the study of the structure and dynamics of the Lyra complex formed of the two clusters RXC J1825.3+3026 and CIZA J1824.1+3029 , very recently studied using both X-ray and radio data .

Methods : This is the first analysis based on kinematics of member galaxies .
New spectroscopic data for 285 galaxies were acquired at the Italian Telescopio Nazionale Galileo and used in combination with PanSTARRS photometry .
The result of our member selection is a sample of 198 galaxies .

Results : For RXCJ1825 and CIZAJ1824 we report the redshifts , z = 0.0645 and z = 0.0708 , the first estimates of velocity dispersion , \sigma _ { v } = 995 _ { -125 } ^ { +131 } km s ^ { -1 } and \sigma _ { v } = 700 \pm 50 km s ^ { -1 } , and dynamical mass , M _ { 200 } = 1.1 \pm 0.4 \times 10 ^ { 15 } M _ { \odot } and M _ { 200 } = 4 \pm 0.1 \times 10 ^ { 14 } M _ { \odot } .
The past assembly of RXCJ1825 is traced by the two dominant galaxies , both aligned with the major axis of the galaxy distribution along the East–West direction , and by a minor North–East substructure .
We also detect a quite peculiar high velocity field in the South–West region of the Lyra complex .
This feature is likely related to a high velocity , very luminous galaxy , suggested to be the central galaxy of a group in interaction with RXCJ1825 by very recent studies based on X-ray and radio data .
The redshift of the whole Lyra complex is z = 0.067 .
Assuming that the redshift difference between RXCJ1825 and CIZAJ1824 is due to the relative kinematics , the projected distance between the cluster centers is D \sim 1.3 Mpc and the line–of–sight velocity difference is \sim 1750 km s ^ { -1 } .
A dynamical analysis of the system shows that the two clusters are likely to be gravitationally bound , in a pre-merger phase , with CIZAJ1824 in front of RXCJ1825 and going toward it .

Conclusions : Our results corroborate a picture where the Lyra region is the place of a very complex scenario of cluster assembly .