Preface -- Part 1 Groups and Geometry -- On flag-transitive c.c*-geometries -- On the 1-cohomology of the groups SL4(2n), SU4(2n), and Spin7(2n) -- About a conjecture of Guralnick and Thompson -- On the Suzuki groups and the outer automorphisms of S6 -- Note on Lie algebras, finite groups and finite geometries -- m-systems and the BLT property -- A block complex collapsing to the Brauer tree -- Some sporadic geometries -- The uniqueness case -- Part 2 Difference Sets -- Exponent bounds for a family of abelian difference sets -- A survey of Hadamard difference sets -- Difference sets in nilpotent groups with large Frattini quotient: geometric methods and (375, 34, 3) -- A difference set construction of Turyn adapted to semi-direct products -- Difference sets in groups of order 4p4 -- A survey on relative difference sets -- Williamson matrices and difference sets -- Note on Paley type partial difference sets -- Part 3 The Monster -- Anti-bracket formalism with the Kähler geometry -- Singular values of Thompson series -- Understanding groups like Γ 0(N) -- The √ Monster construction -- On vertex operator algebras as SL2-modules -- Lattices and generalized Hecke operators -- Codes, loops and p-locals -- A generalization of Kac-Moody algebras -- A note on the elliptic curves of Harada-Lang -- Ternary codes and Z3 -orbifold constructions of conformai field theories -- Non-monstrous moonshine -- Monstrous Moonshine and orbifolds.