THE THIRTEENTH INSTALLMENT of the Istanbul Biennial, curated by Fulya Erdemci, marked a shift in tone. This was an uncompromising exhibition about a world in which our shared spheres of collective freedom are rapidly shrinking. Gone were the warm conviviality and slightly naive hopes of relational aesthetics. Instead, a gloomier and perhaps more realistic atmosphere prevailed in works that relentlessly presented us with barriers and unsurpassable frontiers. Here, art was not expected to offer alternatives to such divided realities, even if Erdemci stressed the presence of social alchemies